Champions Manchester United crushed 10-man Liverpool 3-0 at Old Trafford in a controversial north-west derby.
United took a firmer grip on top spot in the Premier League, but it was the performance of referee Steve Bennett - and Javier Mascherano's lack of control - which will be the talking point.
Mascherano, already booked, was dismissed just before the break for blatant dissent which earned him a second yellow card - and then the red.
The Argentinian had to be hauled from the pitch, such was his anger, and his boss Rafael Benitez was equally unhappy with the incident.
Wes Brown had scored his first goal of the season - and only the third of his career - to give United control at the break, before Ronaldo and Nani netted inside the last 11 minutes as Liverpool tired.
But, in a week which has seen football infuriated by Chelsea's Ashley Cole's escape from dissent aimed at referee Mike Riley, it was hardly surprising Bennett was having none of the same.
Cole should have been sent off at Tottenham in midweek - and Mascherano felt the backlash on Sunday.
The midfielder had been snipping away at Bennett throughout the first period, ably assisted by Fernando Torres.
If television viewers could see the dismissal coming, Mascherano could not.
Torres had been booked for arguing seconds earlier, so when the midfielder continued the debate there was going to be only one winner. Mascherano was incensed, and had to be virtually pulled off the pitch.
United brought back goalkeeper Edwin van der Sar and defender Rio Ferdinand after groin and back injuries respectively, while Paul Scholes and skipper Ryan Giggs also returned.
Liverpool was unchanged after seven straight victories - a run which was to end in the 150th league meeting between these clubs.
The opening tackles were sharp and Mascherano was booked for cutting down Scholes, before Wayne Rooney twice went close.
First the striker got behind Jamie Carragher, whose tackle could easily have produced a penalty had the former Everton man gone down. But the England striker kept his feet and forced Jose Reina into a save with his legs.
Then Scholes' lofted pass fell behind the Liverpool defence, and Reina scooped the ball away from Rooney.
The deadlock was broken in the 34th minute when Rooney's curling cross into the box was met by the unlikely figure of Wes Brown - who reached it before Reina and saw his header drop into the net.
Then Liverpool's frustrations with perceived injustices saw them implode.
First Torres was booked for dissent, and when Mascherano joined in Bennett produced another yellow - and then red.
Gerrard was pushed back into Mascherano's holding role for the second half, which started with Reina making a point-blank save to stop a Ronaldo effort.
Torres, clinical in recent matches, then missed a decent chance when Gerrard's free-kick found him unmarked at the far post, twenty minutes from time.
United sent on Carlos Tevez and Nani for Giggs and Anderson after 73 minutes, and it took another wonder save from Reina to stop Tevez making it 2-0.
Liverpool was incensed by a Michael Carrick challenge on Torres - right in front of Benitez - which Bennett chose not to punish as Reina denied Ronaldo once more with a block that hit the bar and went out for a corner - a flag-kick which proved decisive.
Nani's 79th-minute corner was headed home by