Two goals from Michael Ballack kept alive Chelsea's title hopes as they overcame Manchester United in a pulsating match at Stamford Bridge.

Chelsea's dreams appeared over after an error by Ricardo Carvalho gifted United a 55th minute equaliser to Wayne Rooney.

Ballack had given Chelsea a 45th minute lead and he sealed a vital win by slotting home a penalty five minutes from time.

Referee Alan Wiley awarded the spot-kick after Michael Carrick handled a cross from Michael Essien.

It was a sensational climax to an afternoon of high drama in west London and the win puts Chelsea level on points with United at the top of the Barclays Premier League.

Chelsea set about United in the opening minutes and Michael Essien brought a diving save from Edwin Van der Sar.

Avram Grant's side had to win to keep alive their hopes of stealing the crown from their rivals.

United, who left Cristiano Ronaldo and Carlos Tevez on the substitute's bench, were rocked in the ninth minute when Nemanja Vidic was stretchered off with a facial injury.

The United defender was caught by Didier Drogba's knee as he stooped to head the ball clear and he was subsequently replaced by Owen Hargreaves.

The tempo, as expected, was fast and furious but goalscoring opportunities were at a premium.

Chelsea should have taken the lead in the 20th minute when Joe Cole got clear of the United defence but after initially losing the ball, he lashed a shot against the crossbar from just inside the penalty area.

Chelsea were leaving plenty of gaps in defence but United, with Wayne Rooney operating as a loan striker, were unable to exploit them.

In the 23rd minute a neat combination between Drogba and Essien ended with the Ghanaian's cross eluding everyone in the six-yard box.

Rooney's lone role in attack was clearly not working as Ryan Giggs and Nani were often slow in supporting the England international.

Chelsea continued to press for an opening goal and were unlucky when Joe Cole dribbled his way into the penalty area only for Van der Sar to grab the ball at his feet.

The United 'keeper required treatment for a minor knock as a result of the collision.

On the half-hour Joe Cole shot just wide from the angle of the six-yard box when fed the ball by Essien.

A free-kick from Ashley Cole caused minor panic in the United defence when the giant frame of John Terry rose to meet it but the Chelsea captain could not direct his effort anywhere near the target.

Chelsea took a deserved lead in the 45th minute when Drogba's cross was headed home at the far post by the unmarked Michael Ballack.

Ballack's timely opening goal was just the boost Grant's side had been hoping for.

The Blues, needing to win to move level on points with United at the top of the table, were far the better side in the opening 45 minutes.

United were still struggling to create anything despite a better share of possession at the start of the second half.

United's Brown found himself booked for a foul on Essien in the 52nd minute as, rather ominously for Chelsea, 38-goal Cristiano Ronaldo warmed up on the touchline.

But United got themselves back into the match thanks to a mistake by Chelsea defender Carvalho.

The Portuguese defender passed the ball straight to Rooney who accepted the gift by firing beyond Cech into the net.

Carvalho's error could have already gifted United the title but Sir Alex Ferguson, sensing perhaps that his side could finish the job, replaced a struggling Rooney with Ronaldo.

Seconds later Anderson was substituted for John O'Shea and Chelsea, knowing they had to get themselves back in front, added Nicolas Anelka into the mix in place of Paulo Ferreira.

Referee Wiley awarded a penalty for handball against Carrick in the 86th minute.

The United midfielder got his arm in the way of Essien's cross and Ballack kept his cool to score from the spot and keep the title race on the boil.

United pushed forward and came close to scoring another equaliser but Ashley Cole and Andriy Shevchenko cleared efforts off the line.