Chelsea 1 Everton 1: Chelsea extended their unbeaten home sequence to a record-equalling 63 games yesterday but it came at a cost. The loss of Mikel John Obi to an ankle injury means Chelsea approach Saturday's FA Cup final against Manchester United at Wembley with "only 15 fit players" according to their manager, Jose Mourinho.

It compounds an injury situation that has destabilised the deposed champions this season. "I don't believe we will have 16 fit players," said Mourinho. "Before the game I had a look and I could see how many of the guys behind me were limping; some of them looked like they had come from a battle. (Michael) Ballack - limping. Ricardo (Carvalho) - limping. Arjen Robben.

"It is a final and we want very much to do well and the 11 we have going will have a big spirit."

There was much endeavour yesterday, Mourinho having conveyed to his players his desire for an unbeaten home record to match that of the all-conquering Liverpool side between 1978 and 1980. Success pushed Mourinho's unbeaten run to 98 home games in charge of Chelsea and Porto.

"That's an incredible run," said Everton's manager David Moyes. "It's the same for me in five-a-sides: I've only lost the one, on a rainy night in Shrewsbury." He was in good humour despite missing out on fifth place in the table due to two controversial incidents. Paulo Ferreira's clumsy challenge from behind on Mikel Arteta in the build-up to Didier Drogba's equaliser was then followed by an erroneous offside decision that chalked off what would have been an 88th-minute winner for Everton.

Moyes marched on to the pitch at the injustice of the first incident, prompting his dismissal to the stands. "Where I come from I was taught to stand up when you are right and I stood up for my players there because the decision was wrong," he said.

Moyes's side won the midfield battle with a four-man selection in which Lee Carsley and Manuel Fernandes were bright while Arteta was outstanding.

Drogba had the hunger of a man chasing the Premiership golden boot - his 20th goal of the season here sealed that honour - and Petr Cech made some magnificent saves. Chelsea edged an even first half but after half-time the game burst into life.

Arteta raced from his own half and through the heart of Chelsea's midfield, turning first Mikel and then Wayne Bridge with two deft touches. John Terry, who had been perturbed by the pace of James Vaughan and Leon Osman, backed off the strikers.

The Spaniard made the most of the opportunity with a devastating square pass for Osman. He found Vaughan, who swept his shot past Cech for the goal. Then came the dubious decisions.

Arteta was bundled over by Ferreira but referee Mark Halsey waved appeals away. The ball found its way to Shaun Wright-Phillips via Bridge and the winger's centre set up Drogba's goal, although the Ivorian seemed to shove over Joleon Lescott as Bridge's cross floated over.

Chelsea were lucky to have parity but were even more fortunate come the final whistle. Carsley's drive was saved by Cech, the rebound falling to James McFadden whose shot crept in at the far post. But the goal was ruled out, although the inactivity of James Beattie meant his offside position should have been irrelevant.

Chelsea's unbeaten record remains intact but this result extends the longest winless run under Mourinho's management to five matches. Another such display on Saturday and they will have only the League Cup to show for this season.

• Guardian Service