Manchester City went top of the Premier League with a controversial 2-0 win at Newcastle United and Liverpool kept alive their title hopes with an astonishing 5-3 victory at Stoke City in the Premier League on Sunday.
City won at St James' Park thanks to an early Edin Dzeko goal and a stoppage-time effort from Alvaro Negredo but lost France midfielder Samir Nasri with what looked like a bad knee injury in the closing stages.
City benefited from a contentious decision by referee Mike Jones who disallowed what would have been a superb 34th-minute Newcastle equaliser from Ivorian midfielder Cheick Tiote whose 20-metre volley screamed into the top of Joe Hart's net.
Jones consulted his assistant before ruling that Yoan Gouffran, standing in an offside position, had unsighted Hart, a decision Newcastle boss Alan Pardew fiercely disputed.
The hard-won victory lifted City to 47 points from 21 games, one ahead of Chelsea and two clear of Arsenal, who will return to top spot if they win at Aston Villa on Monday.
Liverpool are fourth on 42 points, ahead of Everton (41), Tottenham Hotspur (40) and Manchester United (37) who all won on Saturday.
The outcome could have been very different if Tiote's goal had counted and the midfielder, who has only scored one goal for Newcastle in 104 appearances, told the BBC: "I think it was a goal and I don't know why the referee didn't accept it.
"We asked the referee to explain why he didn't give the goal, but he didn't say anything so we had to get on with it."
Pardew told Sky Sports he also did not know why the goal was disallowed as he felt Hart's vision was not impaired.
"The referee has not been clear in his answers," he said. "I don't understand it.
"Unfortunately that was a massive call and he has denied it on a tiny technicality here which I think was wrong."
Dzeko swept City into the lead after eight minutes, timing his run perfectly to meet a cross from Aleksandr Kolarov and plant the ball past Tim Krul.
Their second came in the dying seconds when Negredo beat the offside trap and scored at the second attempt, City's 94th goal of the season in all competitions.
"It was a very difficult game and it's a very big result as we know it's a tough place to come and win," City manager Manuel Pellegrini told the BBC.
"It was an offside goal as they were interfering with Joe Hart and the referee made that call," he added.
Frenchman Nasri was carried off on a stretcher with a knee injury after being clattered by defender Mapou Yanga-Mbiwa who was booked for the challenge.
Liverpool raced into a 2-0 lead at Stoke following an own goal from Ryan Shawcross and a Luis Suarez strike.
The home side fought back, however, with a header from former Liverpool player Peter Crouch and a sweet strike by ex-Liverpool midfielder Charlie Adam just before halftime.
Liverpool regained control when Steven Gerrard, making his 650th appearance for the club, converted a penalty before Suarez, the league's top scorer this season, fired home his 22nd league goal of the campaign to make it 4-2.
Jon Walters pulled one back when he turned and fired past goalkeeper Simon Mignolet, but substitute Daniel Sturridge, back after a nine-match injury layoff, scored a fine individual goal to seal Liverpool's first league win at Stoke since the Potteries side were promoted to the Premier League in 2008.
The defeat left Stoke 12th, just four points clear of the relegation zone.