Arsenal's draw allowed fifth-placed Everton to close the gap behind them to six points after Roberto Martinez's won 3-0 at Newcastle.
The Toffees' success was highlighted by Ross Barkley's first-half opener, when the young England midfielder ran from inside his own half and into the home penalty area before coolly converting.
Romelu Lukaku and Leon Osman netted after half-time to keep Everton, who have a game in hand over Arsenal, in the hunt for a Champions League place.
Edin Dzeko's double fired Manchester City closer to the Barclays Premier League summit and poured yet more misery on cross-town rivals United following a 3-0 win.
City were in control from the very first minute when Dzeko tapped into an unguarded net after Samir Nasri's shot deflected off the post and into his path.
A limp United never looked like recovering from the early setback - it was the first time they had conceded a first-minute goal at Old Trafford in the Premier League era - and Dzeko killed off the game on 56 minutes.
Again the striker was allowed too much space as he ran on to a corner and side-footed home a volley at the near post. Yaya Toure completed the rout with a placed finish across David de Gea in injury-time.
City's win, their third on the spin since being knocked out of the Champions League, moves them three points behind leaders Chelsea with two games in hand on the leaders.
Arsenal's forgettable week continued as an injury-time Mathieu Flamini own goal meant they shared a 2-2 draw with relegation-threatened Swansea at Emirates Stadium.
The Gunners had appeared still afflicted by their 6-0 weekend mauling against Chelsea after falling behind to Wilfried Bony's 11th-minute header heading into the last quarter of the game.
Quickfire goals from Lukas Podolski and Olivier Giroud appeared to dramatically turn the game their way. Podolski turned in the equaliser on 73 minutes before he supplied the ball for Giroud to send the Gunners ahead a minutes later.
But Arsene Wenger's side failed to hold on as Flamini put the ball into his own net with no time for the hosts to respond.
TITLE RUN-IN FIXTURES
CHELSEA (Pld 31 Pts 69 GD +39)
Mar 29 - Crystal Palace A
Apr 5 - Stoke H
Apr 13 - Swansea A
Apr 20 - Sunderland H
Apr 27 - Liverpool A
May 3 - Norwich H
May 11 - Cardiff A
MANCHESTER CITY (Pld 29 Pts 66 GD +52)
Mar 29 - Arsenal A
Apr 5 - Southampton H
Apr 13 - Liverpool A
Apr 16 - Sunderland H
Apr 21 - West Brom H
Apr 27 - Crystal Palace A
May 3 - Everton A
May 7 - Aston Villa H
May 11 - West Ham H
LIVERPOOL (Pld 30 Pts 65 GD +44)
Mar 26 - Sunderland H
Mar 30 - Tottenham H
Apr 6 - West Ham A
Apr 13 - Manchester City H
Apr 20 - Norwich A
Apr 27 - Chelsea H
May 3 - Crystal Palace A
May 11 - Newcastle H
ARSENAL (Pld 31 Pts 63 GD +19)
Mar 29 - Manchester City H
Apr 6 - Everton A
Apr 15 - West Ham H
Apr 19 - Hull A
Apr 28 - Newcastle H
May 3 - West Brom H
May 11 - Norwich A
•Chelsea are still in the Champions League, while Arsenal are still in the FA Cup.