|Big-spending City could be in danger of dropping out of the top four unless they rally in the spring [GALLO/GETTY]
Ramires danced through the Manchester City defence to add to David Luiz's 78th-minute header as Chelsea threatened to derail City's season with a 2-0 win at Stamford Bridge.
The defending champions replaced City in third place in the English Premier League, but still lie nine points behind leaders Manchester United after Sunday's result.
Earlier, Liverpool beat Sunderland 2-0 at the Stadium of Light as they continued their recovery under returning boss Kenny Dalglish.
In London, a game of few chances was meandering towards a goalless draw until Brazilian midfielder Luiz earned a free kick and glanced in Didier Drogba's cross to cap another impressive all-round display.
Midfielder Ramires capped things off with a well-taken breakaway goal in stoppage time.
The win took Chelsea to 54 points, one point and one place above City with a game in hand.
Arsenal are second on 58 points with Manchester United top on 63.
Liverpool maintained their chase for a Europa League slot as a fortunate Dirk Kuyt penalty and a great goal by Luis Suarez secured a comfortable 2-0 win at Sunderland.
The Reds were gifted the lead after 33 minutes when John Mensah brought down Jay Spearing just outside the box only for the referee to award a penalty, which Kuyt duly converted.
Suarez made the game safe in the 77th minute when he cut in from the right and, almost from the byline, lashed in shot inside the near post of Simon Mignolet.
Sunderland, who have taken only one point from their last six games, barely created a chance all day but were on the end of another harsh decision five minutes later when Mensah was sent off for bringing down Suarez on the edge of the box.
After being knocked out of the Europa League by Braga on Thursday, sixth-placed Liverpool's only chance of European football next season is if they can finish in the top five and Sunday's win takes them to 45 points, four behind current fifth-placed team Tottenham Hotspur.