diff --git a/app/controllers/api/v1/live/live_controller.rb b/app/controllers/api/v1/live/live_controller.rb
index 2a7a0c9e9ee..8c7af16ee04 100644
--- a/app/controllers/api/v1/live/live_controller.rb
+++ b/app/controllers/api/v1/live/live_controller.rb
@@ -32,19 +32,33 @@ def podiums
   end
 
   def open_round
-    competition_id = params.require(:competition_id)
+    competition = Competition.find(params.require(:competition_id))
     wcif_id = params.require(:round_id)
 
-    round = Round.find_by_wcif_id!(wcif_id, competition_id)
+    round = Round.find_by_wcif_id!(wcif_id, competition.id)
 
     # TODO: Move these to actual error codes at one point
+    return render json: { status: "unauthorized" }, status: :unauthorized unless @current_user.can_manage_competition?(competition)
     # Also think about if we should auto open all round ones at competition day start and not have this check
     return render json: { status: "previous round has empty results" }, status: :bad_request unless round.number == 1 || round.previous_round.score_taking_done?
 
     return render json: { status: "round already open" }, status: :bad_request if round.live_results.any?
 
-    result = round.init_round
+    result = round.open_and_lock_previous(@current_user)
+
+    render json: { status: "ok", locked_rows: result }
+  end
+
+  def quit_competitor
+    competition = Competition.find(params.require(:competition_id))
+    registration_id = params.require(:registration_id)
+
+    return render json: { status: "unauthorized" }, status: :unauthorized unless @current_user.can_manage_competition?(competition)
+
+    round = Round.find_by_wcif_id!(wcif_id, competition.id)
+
+    quit_count = round.quit_from_round!(registration_id, @current_user)
 
-    render json: { status: "ok", added_rows: result.affected_rows }
+    render json: { status: "ok", quit: quit_count }
   end
 end
diff --git a/app/models/live_result.rb b/app/models/live_result.rb
index 096e7df3739..85e74fbe78b 100644
--- a/app/models/live_result.rb
+++ b/app/models/live_result.rb
@@ -14,8 +14,14 @@ class LiveResult < ApplicationRecord
 
   belongs_to :round
 
+  belongs_to :quit_by, class_name: 'User', optional: true
+
+  belongs_to :locked_by, class_name: 'User', optional: true
+
   scope :not_empty, -> { where.not(best: 0) }
 
+  scope :without_quitters, -> { where(quit_by_id: nil).or(where.not(best: 0)) }
+
   alias_attribute :result_id, :id
 
   has_one :event, through: :round
@@ -47,6 +53,10 @@ def best_possible_solve_times
     end
   end
 
+  def mark_as_quit(current_user)
+    update(quit_by_id: current_user.id, advancing: false, advancing_questionable: false)
+  end
+
   def self.compute_average_and_best(attempts, round)
     r = Result.new(
       event_id: round.event.id,
@@ -84,6 +94,6 @@ def notify_users
     end
 
     def trigger_recompute_columns
-      round.recompute_live_columns
+      round.recompute_live_columns(skip_advancing: locked_by.present?)
     end
 end
diff --git a/app/models/round.rb b/app/models/round.rb
index b216da9a142..7f73c8d2029 100644
--- a/app/models/round.rb
+++ b/app/models/round.rb
@@ -44,7 +44,10 @@ def format
   has_many :wcif_extensions, as: :extendable, dependent: :delete_all
 
   has_many :live_results, -> { order(:global_pos) }
-  has_many :live_competitors, through: :live_results, source: :registration
+  has_many :live_results_without_quitters,
+           -> { without_quitters.order(:global_pos) },
+           class_name: "LiveResult"
+  has_many :live_competitors, through: :live_results_without_quitters, source: :registration
   has_many :results
   has_many :scrambles
 
@@ -182,6 +185,13 @@ def advancing_registrations
     end
   end
 
+  def open_and_lock_previous(current_user)
+    init_round
+    return 0 if number == 1 || linked_round.present?
+
+    previous_round.lock_results(current_user)
+  end
+
   def init_round
     empty_results = advancing_registrations.map do |r|
       { registration_id: r.id, round_id: id, average: 0, best: 0, last_attempt_entered_at: current_time_from_proper_timezone }
@@ -193,18 +203,18 @@ def total_competitors
     live_competitors.count
   end
 
-  def recompute_live_columns
+  def recompute_live_columns(skip_advancing: false)
     recompute_local_pos
     recompute_global_pos
-    recompute_advancing
+    recompute_advancing unless skip_advancing
   end
 
   def recompute_advancing
     has_linked_round = linked_round.present?
     advancement_determining_results = has_linked_round ? linked_round.live_results : live_results
 
-    # Only ranked results can be considered for advancing.
-    round_results = advancement_determining_results.where.not(global_pos: nil)
+    # Only ranked results that are not locked can be considered for advancing.
+    round_results = advancement_determining_results.where.not(global_pos: nil).where(locked_by_id: nil)
     round_results.update_all(advancing: false, advancing_questionable: false)
 
     missing_attempts = total_competitors - round_results.count
@@ -353,6 +363,25 @@ def self.wcif_to_round_attributes(event, wcif, round_number, total_rounds)
     }
   end
 
+  def lock_results(locking_user)
+    results_to_lock = linked_round.present? ? linked_round.live_results : live_results
+
+    results_to_lock.update_all(locked_by_id: locking_user.id)
+  end
+
+  def quit_from_round!(registration_id, quitting_user)
+    result = live_results.find_by!(registration_id: registration_id)
+
+    is_quit = result.mark_as_quit(quitting_user)
+
+    return is_quit ? 1 : 0 if number == 1 || linked_round.present?
+
+    # We need to also quit the result from the previous round so advancement can be correctly shown
+    previous_round_results = previous_round.linked_round.present? ? previous_round.linked_round.live_results : previous_round.live_results
+
+    previous_round_results.where(registration_id: registration_id).map { it.mark_as_quit(quitting_user) }.count { it == true }
+  end
+
   def wcif_id
     "#{self.event_id}-r#{self.number}"
   end
diff --git a/config/routes.rb b/config/routes.rb
index 5dac7495f52..18da6d37e55 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -375,6 +375,7 @@
           namespace :live do
             get '/rounds/:round_id' => 'live#round_results', as: :live_round_results
             put '/rounds/:round_id/open' => "live#open_round", as: :live_round_open
+            put '/rounds/:round_id/:registration_id' => 'live#quit_competitor', as: :quit_competitor_from_round
             get '/podiums' => 'live#podiums', as: :live_podiums
             get '/registrations/:registration_id' => 'live#by_person', as: :get_live_by_person
           end
diff --git a/db/migrate/20260128194213_add_locked_by_and_quit_by.rb b/db/migrate/20260128194213_add_locked_by_and_quit_by.rb
new file mode 100644
index 00000000000..28576c403f0
--- /dev/null
+++ b/db/migrate/20260128194213_add_locked_by_and_quit_by.rb
@@ -0,0 +1,10 @@
+# frozen_string_literal: true
+
+class AddLockedByAndQuitBy < ActiveRecord::Migration[8.1]
+  def change
+    change_table :live_results, bulk: true do |t|
+      t.references :quit_by, type: :integer, foreign_key: { to_table: :users }
+      t.references :locked_by, type: :integer, foreign_key: { to_table: :users }
+    end
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index b9ece185fe9..86533c6762c 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[8.1].define(version: 2026_01_26_101113) do
+ActiveRecord::Schema[8.1].define(version: 2026_01_28_194213) do
   create_table "active_storage_attachments", charset: "utf8mb4", collation: "utf8mb4_unicode_ci", force: :cascade do |t|
     t.bigint "blob_id", null: false
     t.datetime "created_at", precision: nil, null: false
@@ -779,10 +779,14 @@
     t.integer "global_pos"
     t.datetime "last_attempt_entered_at", null: false
     t.integer "local_pos"
+    t.integer "locked_by_id"
+    t.integer "quit_by_id"
     t.bigint "registration_id", null: false
     t.bigint "round_id", null: false
     t.string "single_record_tag", limit: 255
     t.datetime "updated_at", null: false
+    t.index ["locked_by_id"], name: "index_live_results_on_locked_by_id"
+    t.index ["quit_by_id"], name: "index_live_results_on_quit_by_id"
     t.index ["registration_id", "round_id"], name: "index_live_results_on_registration_id_and_round_id", unique: true
     t.index ["registration_id"], name: "index_live_results_on_registration_id"
     t.index ["round_id"], name: "index_live_results_on_round_id"
@@ -1579,6 +1583,8 @@
   add_foreign_key "inbox_scrambles", "inbox_scramble_sets"
   add_foreign_key "inbox_scrambles", "inbox_scramble_sets", column: "matched_scramble_set_id"
   add_foreign_key "live_attempt_history_entries", "live_attempts"
+  add_foreign_key "live_results", "users", column: "locked_by_id"
+  add_foreign_key "live_results", "users", column: "quit_by_id"
   add_foreign_key "oauth_openid_requests", "oauth_access_grants", column: "access_grant_id", on_delete: :cascade
   add_foreign_key "payment_intents", "users", column: "initiated_by_id"
   add_foreign_key "paypal_records", "paypal_records", column: "parent_record_id"
diff --git a/spec/factories/live_results.rb b/spec/factories/live_results.rb
index 8a3b8956b92..f7dea25ae82 100644
--- a/spec/factories/live_results.rb
+++ b/spec/factories/live_results.rb
@@ -9,6 +9,9 @@
     average { 5000 }
     last_attempt_entered_at { Time.now.utc }
 
+    locked_by_id { nil }
+    quit_by_id { nil }
+
     transient do
       attempts_count { 5 }
     end
diff --git a/spec/requests/live_recompute_advancing_spec.rb b/spec/requests/live_recompute_advancing_spec.rb
index 255f9531178..40c3893d2c9 100644
--- a/spec/requests/live_recompute_advancing_spec.rb
+++ b/spec/requests/live_recompute_advancing_spec.rb
@@ -111,5 +111,68 @@ def attempt_result_condition
         expect(round.live_results.pluck(:advancing)).to eq([true, true, false, false, false])
       end
     end
+
+    context "with locked results" do
+      it "doesn't change advancing of locked results" do
+        round = create(:round, number: 1, total_number_of_rounds: 2, event_id: "333", competition: competition, advancement_condition: attempt_result_condition)
+
+        5.times do |i|
+          create(:live_result, registration: registrations[i], round: round, average: (i + 1) * 100)
+        end
+
+        expect(round.total_competitors).to eq 5
+        expect(round.competitors_live_results_entered).to eq 5
+
+        round.lock_results(User.first)
+        # Update best/average after locking
+        round.live_results.last.update(average: 50)
+
+        # Advancing is not updated, but ranking is
+        expect(round.live_results.pluck(:global_pos, :advancing)).to eq([[1, false], [2, true], [3, true], [4, false], [5, false]])
+      end
+    end
+
+    context "with quit results" do
+      it "quit from first round excludes from competitors" do
+        round = create(:round, number: 1, total_number_of_rounds: 2, event_id: "333", competition: competition, advancement_condition: attempt_result_condition)
+        registration_1 = registrations.first
+
+        # Open Round
+        round.open_and_lock_previous(User.first)
+
+        # Quit Competitor
+        round.quit_from_round!(registration_1.id, User.first)
+
+        # Quit users is not part of the rounds competitors
+        expect(round.live_competitors.count).to eq 4
+        expect(round.live_competitors.pluck(:registration_id)).not_to include registrations.first.id
+      end
+
+      it "quit from next round marks as no advancing in previous round" do
+        round = create(:round, number: 1, total_number_of_rounds: 2, event_id: "333", competition: competition, advancement_condition: attempt_result_condition)
+        final = create(:round, number: 2, total_number_of_rounds: 2, event_id: "333", competition: competition)
+
+        5.times do |i|
+          create(:live_result, registration: registrations[i], round: round, average: (i + 1) * 100)
+        end
+
+        expect(round.total_competitors).to eq 5
+        expect(round.competitors_live_results_entered).to eq 5
+
+        # Open next round and quit first result from it
+        final.open_and_lock_previous(User.first)
+        final.quit_from_round!(registrations.first.id, User.first)
+
+        # Quit user is marked as not advancing
+        expect(round.live_results.reload.pluck(:global_pos, :advancing)).to eq([[1, false], [2, true], [3, false], [4, false], [5, false]])
+
+        # Quit users is not part of the final round competitors
+        expect(final.live_competitors.count).to eq 1
+        expect(final.live_competitors.first.id).to eq registrations.second.id
+
+        # But still part of the first round competitors
+        expect(round.live_competitors.count).to eq 5
+      end
+    end
   end
 end