Chelsea lost 4-2 at home to Manchester City and Arsenal closed within three points of the Premier League leaders with a 3-1 win at Stoke City marred by a horrific leg injury to Aaron Ramsey Saturday.
City scored a memorable victory at Stamford Bridge where the drama started before kickoff with a first meeting between former Chelsea team mates John Terry and Wayne Bridge since news broke of Terry's alleged affair with Bridge's former girlfriend.
Bridge refused to shake Terry's hand ahead of the game and the City defender emerged the happier man as Chelsea finished with nine men and lost their 37-match unbeaten home record.
Arsenal later inflicted Stoke's first defeat of 2010 when they came from behind to win 3-1.
The victory though was overshadowed by a serious injury to Wales midfielder Ramsey who was taken straight to hospital with a suspected broken leg after a challenge from defender Ryan Shawcross that earned a red card.
The reaction of the players was reminiscent of when Arsenal's Eduardo da Silva broke his leg against Birmingham City two years ago.
Danny Pugh had put Stoke ahead but a header from Nicklas Bendtner, a penalty by Cesc Fabregas and a tap-in from Thomas Vermaelen in stoppage time gave Arsenal the points.
Chelsea stay top with 61 points from 28 matches, one ahead of Manchester United (60) who meet Aston Villa in the League Cup final Sunday. Arsenal are third on 58 points.
Manchester City have 49 points in fourth spot, one place above Tottenham Hotspur (46) who play Everton Sunday.
Bottom club Portsmouth ended a traumatic week, when they were placed in administration and sustained a nine-point penalty deduction to virtually seal relegation, by winning 2-1 at second-bottom Burnley.
Pompey, who had Ricardo Rocha sent off, won with a goal from Frederic Piquionne and a penalty by Hassan Yebda.
Bolton Wanderers climbed out of the bottom three with a 1-0 win over Wolverhampton Wanderers, Zat Knight scoring.
The match at Stamford Bridge took centre stage though and after a forgettable 42 minutes the game came to life as Frank Lampard shot Chelsea ahead.
City levelled before halftime when Tevez pounced on a long punt up field from Bridge.
Chelsea never recovered their composure and eventually suffered their first home defeat since November 2008.
Tevez, who scored twice, was back for City after returning from compassionate leave in Argentina following the premature birth of his second daughter last week.
"It has been a difficult week ... but it's OK and I have played and scored. I always like playing against Chelsea and always score against them. Sorry Chelsea," Tevez said.
Craig Bellamy put City 2-1 ahead six minutes into the second half with an angled shot after a driving run.
Juliano Belletti was sent off in the 75th minute after tripping Gareth Barry and Tevez made it 3-1 from the spot.
Michael Ballack was then dismissed for a tackle from behind on Tevez before Bellamy tapped in at the far post after a quick break from former Chelsea winger Shaun Wright-Phillips.
Lampard then converted a late penalty after Barry tripped Nicolas Anelka.