Joe Hart produced a stunning penalty save to deny Frank Lampard as Manchester City kept neighbours United within 12 points by beating Chelsea on Sunday, while Newcastle eased their relegation fears with victory at home to Southampton.
Roberto Mancini has been a heavy critic of Manchester City 'keeper Hart in recent weeks, but he delivered a monumental save at a crucial time to help the champions to a 2-0 triumph over Chelsea. The scores were goalless when Hart got a strong hand to Lampard's 52nd-minute spot-kick, and moments later Yaya Toure opened the scoring before Carlos Tevez wrapped things up.
City - knowing they simply had to win to keep their title defence alive - started strongly on home soil, forcing a fine stop from Petr Cech as Matija Nastasic met an in-swinging corner from the right. Sergio Aguero then wasted another glorious opening when he found himself one-on-one with Cech, forcing the ball too wide when trying to round the keeper.
Jack Rodwell was next to keep the Chelsea shot-stopper busy with a 25-yarder that needed turning over, and from the resulting corner the former Everton man headed tamely straight at Cech.
Chelsea had to wait until the second period for their first major opening, but it was a pivotal moment as Hart raced from his goal to bring down Demba Ba. England colleagues Lampard and Hart eyeballed each other from 12 yards, but the latter won the battle with a brilliant low save to his right.
Within ten minutes Toure punished Lampard's error with a goal of exceptional quality. Receiving the ball on the edge of the box, he accelerated into the inside-left channel before opening his body to guide a measured effort across Cech into the far corner.
It was a deserved lead for City, who were the better side throughout, and they eventually earned a scoreline to reflect that control when Tevez buried a late second, picking the ball up on the edge of the area before slamming right-footed past Cech's right hand.
Newcastle are now six points clear of the relegation zone after Southampton left St James' Park with a 4-2 defeat. Saints, who fall to 16th, were undone by strikes from Moussa Sissoko, Papiss Cisse and Yohan Cabaye - in addition to a Jos Hooiveld own goal - in a highly entertaining contest.
Southampton led as early as the third minute, with Rickie Lambert nodding Jack Cork's cross into the path of Morgan Schneiderlin. The French midfielder swivelled and fired goalwards, beating Rob Elliot at his near post.
Newcastle took half an hour to respond, and Saints keeper Artur Boruc was unlucky when the goal arrived, making a fine block to deny Yoan Gouffran only to see Sissoko tap home the rebound.
By half-time the game had been turned on its head as Cisse blasted Newcastle ahead in typically spectacular style. A goal of the season contender, Cisse lashed a bouncing ball over Boruc from 25 yards to raise the noise levels considerably inside St James' Park.
Saints are a spirited side and they levelled five minutes after the break through Lambert's 100th goal for the club. But they could not plug the gaps at the back and Danny Fox was guilty of handball to allow Cabaye to net from the spot, before Hooiveld's own goal finally settled the match.