Tevez nods in for his first goal for Man Utd

Chelsea put in a resolute showing but had Mikel Jon Obi harshly sent-off for a rash tackle on Patrice Evra.

United then went ahead after first-half injury-time had elapsed with a near post Carlos Tevez header.

Chelsea stubbornly kept the deficit to one goal until Louis Saha's spot-kick after a foul on him by Tal Ben Haim.

The Chelsea players had been firmly under the microscope at the start of the game after Mourinho's exit and came away with their pride intact after a battling display.

They traded high-five's and hugs in a show of unity as they gathered together just before kick-off.

But, if there was any semblance of fragility about the Blues's resolve, United quickly tried to expose it.

United striker Wayne Rooney cut inside Ben Haim on the edge of the box and curled a shot on the visitors goal which keeper Petr Cech finger-tipped wide at full-stretch.

Chelsea heeded the warning to duly get into their stride and produced some promising periods of play only to squander their good work with poor decisions and a lack of cutting edge in the final third.

The home side were denied a penalty when a sliding Joe Cole appeared to make contact with Evra ahead of getting a touch on the ball before Giggs then wasted a gilt-edged chance.

Michael Essien gave the ball away to Rooney and he crossed for Giggs, who side-footed a volley high from a tight angle at the far post.

Chelsea's test of character suffered a setback Mikel was sent-off when he led with his studs as he chased down the ball and their brave resistance finally buckled on the stroke of half-time.

Giggs curled an outswinging cross to the near post with the outside of his left foot and Tevez got his head to the ball before Cech to head in his first goal for the club.

Chelsea will be unhappy referee Mike Dean did not blow for half-time before the goal as the allotted two minutes of added time had already elapsed.

United put on a professional performance and pressed for a second after the break.

Giggs blazed a volley high but the home side struggled to create any further chances as a determined Chelsea held them at arm's length.

Chelsea hoped to snatch an equaliser but their hopes were ended when Saha stroked in a penalty to move United up to second and leave the visitors five points adrift of top place in the Premiership.