English FA Premiership/ Chelsea 1 Charlton Athletic 1: As if it had not been a strange enough weekend in London with a whale in the Thames, events took an even more unusual twist yesterday. For the first time in nine months and 14 matches, Chelsea failed to win at home in the Premiership.

Unfortunately for their closest rivals, Wally's death on a barge is unlikely to be followed by the expiry of Chelsea's title challenge. "When they think how far ahead we are, they will go from a smile to (a scowl)," Jose Mourinho said.

Charlton will still enjoy their achievement and must be the only team who relish visits to Chelsea. They won here on penalties in the League Cup in October and deserved this draw, secured by a debut goal from the substitute Marcus Bent.

It had been hard during the first half to imagine Charlton avoiding defeat as Chelsea took the lead and cruised, but an improved display brought an equaliser and might have delivered a winner.

The late dismissal of Ricardo Carvalho for a second booking capped the disappointment for a subdued Chelsea, who paid for not taking chances to extend their lead before the interval.

They seemed to be playing within themselves at that stage as Charlton posed scant threat, and found it difficult to go up through the gears after Bent's goal. Lacking cutting edge they rarely looked like rescuing an 11th straight Premiership victory.

"When you arrive in January and lose your first two points at home, I think that's a magnificent achievement," said Mourinho, whose team's most recent failure to win in the league here was against Arsenal last April.

"When you don't win at home you always feel a taste you don't like but in the context of the Premiership we have one more point and one less game to play and we are going in the direction of the title, so it's not too bad."

Few of his players rose above the ordinary on a poor pitch. There were flashes from Joe Cole but some unsuccessful showiness, too, and Damien Duff faded. Hernan Crespo was rarely prominent, even if his header was fumbled by Thomas Myhre to enable Eidur Gudjohnsen to score and he was wrongly given offside when through late on. Mourinho said Charlton were "lucky to have a linesman that gave them a big help".

Gudjohnsen and Frank Lampard were involved in many of Chelsea's best moments but neither dominated the game, and Mourinho's defence had one of its less assured afternoons once Charlton gained momentum. Carvalho was below par and Asier Del Horno failed to impress. Bent ran off him to score and Luke Young later skipped round the left back to set up a presentable chance which Darren Bent fired over.

The best individual performances came from Charlton, with Darren Ambrose the pick. He set up Marcus Bent's goal and might have won the match in the 84th minute when denied by Petr Cech.

Matt Holland did well after the interval as Charlton defended well, and Marcus Bent could be satisfied. He was brought on in the 40th minute after Young hurt Dennis Rommedahl when jumping for a header. The change helped Charlton by giving their 4-5-1 formation more of a goal threat, with the substitute drifting off the right flank towards the box. Darren Bent had been too isolated earlier.

Marcus Bent took his goal well, running on to Ambrose's chip and flicking a header over the onrushing Cech from near the penalty spot with his back to goal. That gave Charlton a confidence which made sure that, for the first time in 42 matches, Chelsea went ahead in a league game but did not win.

Alan Curbishley will trust his team do not now lose six matches in a row, as after their League Cup success here.

"A result like today goes a long way to getting us back on track," he said.

Charlton had fallen behind when Chris Powell allowed Crespo a free header from a corner and Gudjohnsen forced the ball over the line.

When Lampard sent an overhead volley just wide and Del Horno had a header kicked off the line, Chelsea must have felt a win was coming but a revived Charlton surprised them.

Maniche speeded up the tempo for Chelsea after coming on but Mourinho must have sensed it would not be his day when Carvalho was dismissed for a second foul on Darren Bent, another red card after Arjen Robben's a week earlier at Sunderland.

"I don't agree with the sending off but we are a clean team. I am not angry and I am not frustrated. I know how football is. I know you cannot win every game. But the record we have is fantastic so I am happy.

"This day had to arrive some day and arrived against a team that was well-organised, defended well and always showed danger in the counter-attack," said Mourinho.