An Andre Schurrle hat-trick saw Chelsea stretch their lead in the Premier League on Saturday, while Newcastle United manager Alan Pardew was sent off for headbutting an opposition player.
Germany international Schurrle scored three times in 17 second-half minutes as Chelsea won 3-1 at Fulham and a 1-0 loss for Arsenal at Stoke City left Jose Mourinho's side with a four-point lead over their London rivals.
Arsenal manager Arsene Wenger described his side's result as a "massive setback" and his misery was compounded later in the day when Liverpool moved above Arsenal into second place following a 3-0 win at Southampton.
At Craven Cottage, new Fulham manager Felix Magath was overseeing his first home game and he almost saw his side take an early lead when Clint Dempsey headed wide from close range.
However, after Fulham goalkeeper Maarten Stekelenburg had saved from Fernando Torres just before half-time, Schurrle made the breakthrough in the 52nd minute when he ran through to score from a lofted Eden Hazard pass.
Hazard teed up Schurrle for his second goal in the 65th minute before Torres released the former Bayer Leverkusen man for his third goal four minutes later.
Victory extended Chelsea's lead to six points over Manchester City, who have two games in hand, while Fulham, who replied through Jonny Heitinga, remain four points adrift of safety at the foot of the table.
"At half-time, I told them nothing," said Chelsea manager Mourinho. "Nothing, not a word. I walked in, then I walked out. I don't know if anyone else gave a team talk. The second half was a great reaction to the worst performance of the season.
"We have four points more than Arsenal. The gap to Man City is a fake advantage. If they win their games in hand, they're top of the league. We're behind them."
Unlike City, who tackle Sunderland in Sunday's League Cup final, Arsenal do not have the consolation of any games in hand on Chelsea after their defeat at Stoke.
Wenger had Mesut Ozil back in his squad after injury, but he saw his side beaten by a 76th-minute Jonathan Walters penalty after Laurent Koscielny had been penalised for handball.
"It is not slightly worrying, it is a big worry for us to lose a game like that. It's a massive setback," said Wenger. "In a game like that, we didn't produce the performance we wanted. To win a title when you are expected to perform, you have to perform. It's as simple as that."
Suarez marks milestone
Arsenal's defeat, their fifth of the season, enabled Liverpool to steal above them on goal difference after their success at Southampton.
Luis Suarez opened the scoring in the 16th minute, sweeping home after Jose Fonte had inadvertently gifted him the ball to mark his 100th Premier League appearance with a 62nd league goal.
In reply, Adam Lallana hit the post for Southampton, but Raheem Sterling made it 2-0 in the 58th minute with his first touch after coming on as a substitute before Steven Gerrard added a stoppage-time penalty.
"We dropped points here last year (losing 3-1) and we have learned our lesson," said Liverpool captain Gerrard. "We made the decision to leave our two up front all the time, and if teams want to go two-on-two against Luis Suarez and Daniel Sturridge, then all the best."
Newcastle won 4-1 at Hull, but the match was overshadowed by Pardew's dismissal for aiming a headbutt at home midfielder David Meyler.
Pardew was sent to the stands after inclining his head towards Meyler during a second-half touchline confrontation and Football Association chairman Greg Dyke subsequently announced that his organisation would investigate the incident.
Pardew issued a public apology moments after the final whistle, telling Sky Sports: "It was a heat-of-the-moment thing. I massively regret it and I will have to sit down from now on.
"Of course, I didn't mean to do anything aggressive. I did move my head forward, and that's enough. Of course I apologise. I represent a big club."
Moussa Sissoko scored twice for Newcastle, with Loic Remy and Vurnon Anita also on target, while Curtis Davies replied for Hull.
Meanwhile, Romelu Lukaku marked his return from a month-long absence with an ankle injury by coming off the bench to score the winning goal for Everton in a 1-0 win at home to West Ham United.
The Belgian slammed home from Leighton Baines's pass in the 81st minute to end West Ham's run of four consecutive wins and take Everton to within two points of fifth-place Tottenham Hotspur.
