Arsene Wenger's 1,000th match in charge of Arsenal ended in one of his heaviest humiliations — a 6-0 collapse at Chelsea — and included the referee ejecting the wrong player from Arsenal on Saturday.
Although Luis Suarez scored three of Liverpool's six against Cardiff and Yaya Toure claimed a hat trick for Manchester City against Fulham, the goal of the day saw Manchester United's Wayne Rooney lobbing the ball from inside the halfway line at West Ham.
Here is a look at the action from Europe's top leagues on Saturday:
At Stamford Bridge, Andre Marriner apologized to Arsenal for dismissing Kieran Gibbs instead of teammate Alex Oxlade-Chamberlain, whose diving save with his hand blocked the ball on the goal line.
The 15th-minute ejection was hardly a turning point in the London derby, however, as Arsenal had already conceded twice inside seven minutes in Wenger's landmark match on goals by Samuel Eto'o and Andre Schuerrle.
Arsenal crumbled further against the leaders after Eden Hazard converted the penalty kick, with Oscar scoring twice before Mohamed Salah completed the rout.
Manchester City climbed above Arsenal into third place with a 5-0 victory over bottom-place Fulham, while second-place Liverpool won 6-3 at Cardiff. It leaves Chelsea four points ahead having played one more match than Liverpool and three more than City, which is six adrift.
Far from the title race is Manchester United, which remains seventh despite Rooney scoring twice in a 2-0 victory at West Ham.
Bayern Munich waited until late to grind out a 2-0 win in Mainz, with Bastian Schweinsteiger and Mario Goetze scoring in the last 10 minutes as the team's unbeaten run stretched to a record 51 games.
Second-place Borussia Dortmund won 3-0 at Hannover, but remained 23 points behind Bayern with eight games remaining. Bayern can secure the quickest title in 51 years of the Bundesliga by winning at Hertha Berlin on Tuesday.
Marseille extended its poor run of form with a 1-0 loss at home to relegation-threatened Rennes in the French league, a third defeat in four games for the sixth-place team.
It was Rennes' second win in seven matches and saw it end a run of three consecutive defeats and provisionally move six points clear of the relegation zone.
Athletic Bilbao provisionally stretched its fourth-place advantage while compounding Getafe's miserable run when Markel Susaeta clinched a 1-0 victory.
Bilbao moved nine points clear of Real Sociedad in the race to clinch the league's final Champions League qualifying spot. Getafe remained one point above the drop zone after its winless run was extended to 14 games.
Ciro Immobile netted a hat trick to become Serie A's top scorer with 16 goals and Torino beat relegation-threatened Livorno 3-1.
The win reignited its European hopes as a run of four consecutive defeats ended, although it was provisionally seven points behind sixth spot. Livorno remained a point above the relegation zone.