diff --git a/app/controllers/matches_controller.rb b/app/controllers/matches_controller.rb
index ac40b8f..8a83897 100644
--- a/app/controllers/matches_controller.rb
+++ b/app/controllers/matches_controller.rb
@@ -45,12 +45,8 @@ class MatchesController < ApplicationController
     Match.transaction do
       if @match.update(match_params)
         handle_match_end if new_state == 'finished'
-        if @match.group_match? && new_state == 'in_progress'
-          group = @match.group
-          unless UpdateGroupsGroupScoresAndSave.call(group: group).success?
-            logger.warn "Updating groups group score failed for #{group}"
-          end
-        end
+        handle_match_stop if new_state == 'not_started'
+        update_group_scores if @match.group_match? && %w[in_progress not_started].include?(new_state)
 
         render json: @match
         synced_tournament = @match.tournament
@@ -113,6 +109,19 @@ class MatchesController < ApplicationController
     raise ActiveRecord::Rollback
   end
 
+  def handle_match_stop
+    @match.match_scores.each do |match_score|
+      match_score.update!(points: 0, hidden_points: 0)
+    end
+  end
+
+  def update_group_scores
+    group = @match.group
+    return if UpdateGroupsGroupScoresAndSave.call(group: group).success?
+
+    logger.warn "Updating groups group score failed for #{group}"
+  end
+
   def validate_params
     case match_params['state']
     when 'in_progress'
@@ -121,6 +130,9 @@ class MatchesController < ApplicationController
     when 'finished'
       render json: { error: 'Match can\'t finish in this state' }, status: :unprocessable_content \
         unless @match.in_progress?
+    when 'not_started'
+      render json: { error: 'Match can\'t stop in this state' }, status: :unprocessable_content \
+        unless @match.in_progress?
     else
       render json: { error: 'Invalid target state' }, status: :unprocessable_content
     end
diff --git a/spec/controllers/matches_controller_spec.rb b/spec/controllers/matches_controller_spec.rb
index 96253c2..ed1a5a0 100644
--- a/spec/controllers/matches_controller_spec.rb
+++ b/spec/controllers/matches_controller_spec.rb
@@ -233,6 +233,21 @@ RSpec.describe MatchesController, type: :controller do
             expect(body[:state]).to eq(valid_update[:state])
           end
 
+          it 'stops an in-progress match and resets its scores' do
+            @match.update!(state: :in_progress)
+            @match.match_scores.each do |match_score|
+              match_score.update!(points: 7, hidden_points: 5)
+            end
+
+            expect(TournamentLiveBroadcast).to receive(:call).with(@match.tournament.id)
+            put :update, params: { id: @match.to_param, state: 'not_started' }
+
+            expect(response).to be_successful
+            expect(@match.reload.state).to eq('not_started')
+            expect(@match.match_scores.reload.map(&:points)).to all(eq(0))
+            expect(@match.match_scores.reload.map(&:hidden_points)).to all(eq(0))
+          end
+
           context 'on a running playoff match' do
             let(:finished) do
               {
@@ -385,6 +400,14 @@ RSpec.describe MatchesController, type: :controller do
             expect(response).to have_http_status(:unprocessable_content)
           end
         end
+
+        context 'with stop params on a not-started match' do
+          it 'renders an unprocessable entity response' do
+            put :update, params: { id: @match.to_param, state: 'not_started' }
+            expect(response).to have_http_status(:unprocessable_content)
+            expect(deserialize_response(response)[:error]).to eq("Match can't stop in this state")
+          end
+        end
       end
 
       context 'as another user' do
@@ -401,6 +424,34 @@ RSpec.describe MatchesController, type: :controller do
       end
     end
 
+    context 'on a running group match' do
+      let(:tournament) { create(:group_stage_tournament, group_count: 1, match_factory: :filled_group_match) }
+      let(:group) { tournament.stages.find_by(level: -1).groups.first }
+      let(:group_match) { group.matches.first }
+
+      before do
+        apply_authentication_headers_for tournament.owner
+        group_match.update!(state: :in_progress)
+        group_match.match_scores.order(:id).each_with_index do |match_score, index|
+          match_score.update!(points: index.zero? ? 9 : 2, hidden_points: index.zero? ? 4 : 1)
+        end
+        UpdateGroupsGroupScoresAndSave.call(group: group)
+      end
+
+      it 'stops the match, clears scores, and recalculates group scores' do
+        put :update, params: { id: group_match.to_param, state: 'not_started' }
+
+        expect(response).to be_successful
+        expect(group_match.reload.state).to eq('not_started')
+        expect(group_match.match_scores.reload.map(&:points)).to all(eq(0))
+        expect(group_match.match_scores.reload.map(&:hidden_points)).to all(eq(0))
+        involved_group_scores = group.group_scores.reload.select { |score| group_match.teams.include?(score.team) }
+        expect(involved_group_scores.map(&:group_points)).to all(eq(0))
+        expect(involved_group_scores.map(&:scored_points)).to all(eq(0))
+        expect(involved_group_scores.map(&:received_points)).to all(eq(0))
+      end
+    end
+
     context 'on a playoff match that isn\'t ready yet' do
       let(:invalid_update) do
         {
diff --git a/spec/e2e/http/api_surface_spec.rb b/spec/e2e/http/api_surface_spec.rb
index b63963c..d72a158 100644
--- a/spec/e2e/http/api_surface_spec.rb
+++ b/spec/e2e/http/api_surface_spec.rb
@@ -270,11 +270,14 @@ RSpec.describe 'Backend API surface HTTP E2E' do
     started_match = anonymous_client.get("/matches/#{match.fetch(:id)}")
     score_to_update = started_match.fetch(:json).fetch(:match_scores).first
     score_show = anonymous_client.get("/match_scores/#{score_to_update.fetch(:id)}")
-    score_update = owner_client.patch("/match_scores/#{score_to_update.fetch(:id)}", body: { points: 7 })
+    score_update = owner_client.patch("/match_scores/#{score_to_update.fetch(:id)}", body: { points: 7, hidden_points: 11 })
     forbidden_score_update = other_client.patch("/match_scores/#{score_to_update.fetch(:id)}", body: { points: 3 })
     unauthenticated_score_update = anonymous_client.patch("/match_scores/#{score_to_update.fetch(:id)}", body: { points: 3 })
     bet_while_running = owner_client.post("/matches/#{match.fetch(:id)}/bets", body: { team: team.fetch(:id) })
     restart_started_match = owner_client.patch("/matches/#{match.fetch(:id)}", body: { state: 'in_progress' })
+    stop_started_match = owner_client.patch("/matches/#{match.fetch(:id)}", body: { state: 'not_started' })
+    stopped_match = anonymous_client.get("/matches/#{match.fetch(:id)}")
+    restop_match = owner_client.patch("/matches/#{match.fetch(:id)}", body: { state: 'not_started' })
     playoff_stats = anonymous_client.get("/tournaments/#{playoff_only.fetch(:id)}/statistics")
     tied_playoff_match = playoff_only.fetch(:stages)
                                      .flat_map { |stage| stage.fetch(:matches) }
@@ -349,12 +352,21 @@ RSpec.describe 'Backend API surface HTTP E2E' do
     expect(score_show[:status]).to eq(200)
     expect(score_update[:status]).to eq(200)
     expect(score_update.dig(:json, :points)).to eq(7)
+    expect(score_update.dig(:json, :hidden_points)).to eq(11)
     expect(forbidden_score_update[:status]).to eq(403)
     expect(unauthenticated_score_update[:status]).to eq(401)
     expect(bet_while_running[:status]).to eq(422)
     expect(bet_while_running.dig(:json, :error)).to eq('Betting is not allowed while match is in_progress')
     expect(restart_started_match[:status]).to eq(422)
     expect(restart_started_match.dig(:json, :error)).to eq("Match can't start in this state")
+    expect(stop_started_match[:status]).to eq(200)
+    expect(stop_started_match.dig(:json, :state)).to eq('not_started')
+    expect(stopped_match[:status]).to eq(200)
+    expect(stopped_match.dig(:json, :state)).to eq('not_started')
+    expect(stopped_match.dig(:json, :match_scores).map { |score| score.fetch(:points) }).to all(eq(0))
+    expect(stopped_match.dig(:json, :match_scores).map { |score| score.fetch(:hidden_points) }).to all(eq(0))
+    expect(restop_match[:status]).to eq(422)
+    expect(restop_match.dig(:json, :error)).to eq("Match can't stop in this state")
 
     expect(playoff_stats[:status]).to eq(501)
     expect(playoff_stats[:json]).to eq({})