Chelsea's manager Andre Villas-Boas (R) reacts during their English Premier League soccer match as Manchester City manager Roberto Mancini (L) watches play at Stamford Bridge in London, Dec 12, 2011. [Photo/Agencies]

LONDON - Frank Lampard came off the bench to convert a late penalty as Chelsea beat Manchester City 2-1 on Monday to inflict the Premier League leaders' first defeat of the season and lift themselves back into title contention.

City, reduced to 10 men for the last half hour, had wasted no time getting off the mark when Mario Balotelli netted in the second minute after a delightful through-ball from Sergio Aguero.

Chelsea then weathered a literal and metaphorical storm as City dominated the opening period at a blustery and rainy Stamford Bridge and were lucky not to concede a penalty before levelling through a Raul Meireles volley in the 34th minute.

That goal and the 58th-minute sending off of City left back Gael Clichy raised the home side's spirits and when Joleon Lescott handled Daniel Sturridge's shot, substitute Lampard fired home from the penalty spot on 83 minutes.

City's first defeat in 15 matches opened up the title race.

They have 38 points, two ahead of champions Manchester United and seven clear of third-placed Chelsea and Tottenham Hotspur.

"We needed to do our job to get our Premier League challenge back on track and I think it's pretty much alive now," Chelsea manager Andre Villas-Boas told Sky Sports.

"Our objective was to shorten the distance to the leaders today, we managed to do exactly that, we don't take an extra flavour from being the first team to beat them."

Chelsea's Frank Lampard shoots and scores a penalty against Manchester City during their English Premier League soccer match at Stamford Bridge in London Dec 12, 2011. [Photo/Agencies]

City manager Roberto Mancini said his side had faced an uphill task with 10 men but that the real turning point had been the penalty that should have been given when David Silva was caught on the knee by Jose Bosingwa's shin in the area

"The referee was there ... this changed the game," he said.

"We can do nothing, we are the top, we know that it was possible to lose one game ... I hope we can do another 14 games without losing."

City had sought to give a quick answer to questions over what effect last week's Champions League exit might have on their domestic campaign as they raced into an early lead.

Aguero saw the space in the Chelsea defence to send a pin-point pass from the outside of his right foot to Balotelli, who rounded keeper Petr Cech and calmly slotted the ball in.

The Italian striker greeted his goal with something much closer to a celebration than his usual nonchalance, half raising his arms as a flicker of a smile crossed his lips.

Manchester City's Gael Clichy (R) is sent off by referee Mark Clattenburg during their English Premier League soccer match against Chelsea at Stamford Bridge in London, Dec 12, 2011. [Photo/Agencies]