Chelsea 2 Manchester United 1: Ballack puts race in balance

German does the double to keep Chelsea's title challenge alive as Ferguson rages at 'diabolical' penalty decision

Like the leader of a marathon developing cramp, Manchester United are limping towards the finishing line and suddenly looking over their shoulder. After an enthralling 90 minutes of football – 99 if all the added time is included – a defiant Chelsea are right there with them and ready for the final sprint, though two factors still count against them.

Firstly, if the teams remain level on points, United's goal difference, currently superior by 16, would win them the title. Secondly, Chelsea's next game, at Newcastle tomorrow week, is the hardest of the remaining four that the two contenders face.

United will be expected to win at home to West Ham two days before that and must then visit Steve Bruce's Wigan on the final weekend, when Chelsea will be optimistic about defeating Bolton at Stamford Bridge. Both camps nevertheless had reason to believe as the dust settled early yesterday afternoon. The much-criticised Chelsea manager, Avram Grant, said: "I think we can win the title. In sport, you need to be optimistic. The spirit and courage of the players was great."

The lugubrious Grant had even shown a touch of emotion as the final whistle ended United's furious late rally, in which two attempts were kicked off the line. His smile was reciprocated by the crowd, who greetedhim more warmly than at any time since he became the unpopular replacement for Jose Mourinho in September.

After he lost his first game2-0 at Old Trafford, Chelsea were sixth in the table, and by Christmas trailed United by eight points. How they have come to regret two recent last-minute goals: Emile Heskey's for Wigan at the Bridge and, five days later, the one Carlos Tevez nodded in for United at Blackburn. Those defining moments represented a swing of three points United's way, which is just as well for them, since they have now won only one of their last four games.

At a time when they might have expected to be sitting pretty,United are experiencing what Sir Alex Ferguson calls "squeaky bum time". He still believes the experience he and his squad have gleaned will help them to achieve the club's 17th championship – only one fewer than Liverpool – and a 10th in the past 16 seasons. After admitting: "Chelsea were the better team in the first half," he railed against the award of the first penalty given against Unitedthis season, which allowed Michael Ballack to score his second goal and win the game in the 86th minute.

"It was absolutely diabolical," Ferguson said. "It's a major decision. Granted it has hit Michael Carrick's hand but he's not lifted his hand. If it goes down to decisions like that, we're in trouble and are going to have to perform really well. But in the second half we played very well and it's still in our hands."

The penalty decision was made by a well-placed assistant refereerather than Alan Wiley, who might have issued more than six yellow cards (four of them to United) on a feisty occasion that never quite boiled over until half-a-dozen United players were warming down afterwards. Patrice Evra was reported to have been involved in an altercation with groundstaff after taking exception to a remark by one of them. Later, Rio Ferdinand apologised for accidentally kicking a female steward in his frustration at the result.

After Ballack headed Chelsea into the lead just before half-time, Rooney had taken advantage of a dreadful error by the otherwise impeccable Ricardo Carvalho to equalise. But Chelsea's win, however controversially achieved, was well deserved. Michael Essien, Ballack and John Obi Mikel compensated splendidly for the absent Frank Lampard, and Joe Cole was back to his lively old self.

United fans holding a banner reading "Champions" even before kick-off must have been concerned by the way Chelsea dominated from the first minute, when Wes Brown's careless back-header, spilled by Edwin van der Sar, was an ominous start. Midway through the half Joe Cole, having apparently missed his chance, smacked a shot against the angle of bar and post; and in added time before the interval Ballack headed Essien's perfect cross just inside the post.

The home side were in control when Paulo Ferreira decidedto take a short free-kick in his own half to Carvalho, who even more inexplicably flicked it straight to Rooney. The England striker hared off and finished superbly. Didier Drogba, having won an argument with Ballack over who should take a free-kick, saw Van der Sar save it brilliantly,but the goalkeeper could do nothing about the German's penalty. The drama was not done: in five minutes of added time, Ashley Cole and the substitute Andriy Shevchenko both had to hack off the line.

As a possible rehearsal for the Champions' League final, which these two are marginal favourites to reach, everyone outside Anfield and the Nou Camp will be urging: bring it on.