Chelsea 1, Aston Villa 0: It is extraordinary to think that, not long ago, serious questions were being asked about whether Damien Duff had a future at Chelsea. The arrival of Arjen Robben provoked suggestions that the Dubliner might fall out of favour here. But any thoughts that those two could not play in the same team were destroyed a while back and yesterday Duff showed his undoubted value.

He not only got Chelsea's winner, set up fittingly by Robben, but was involved in most of his team's better moments before he faded in the second half. With six goals from his past eight starts, Duff is certainly doing his bit to keep the club rolling towards what they hope will be a first title since 1955.

Together with Robben, and occasionally Frank Lampard, Duff carried Chelsea's greatest threat. That menace was more intermittent than the fans have become used to here but the leaders did enough to see off a diligent but uninventive Aston Villa and stay five points clear at the top.

Though Villa could not be faulted for effort and generally defended well, they rarely looked like equalising once Duff had scored after half an hour. Chelsea saw off pockets of pressure.

If Robben has tended to attract more plaudits than Duff, his fellow wide man's work has been just as vital of late. Duff's six most recent strikes have been opening goals, and that ability to make the breakthrough is crucial.

Manager Jose Mourinho was full of praise for Duff, noting not just the player's attacking efforts but his defensive work. "I think he's playing fantastically," said the manager. "Duff and Robben, everybody thought only one could play and in this team they play together and it's not a problem for them and it's fantastic for the team.

"They can play left and right, inside and outside, they can shoot and cross. They have all these things in their pocket. They are doing that fantastically but also their defensive contribution is fantastic.

"I took Damien off because I know 15 minutes for Damien means about two miles (of running). If I can give him two miles' rest, it's important."

At the halfway point of the season Duff has as many goals (seven) as he managed in 40 matches for Chelsea last season. He had also sent a vicious shot just wide before his goal and just failed to connect with a Robben cross.

Mourinho puts Duff's goalrush down to his changed role in the side. "I think Chelsea last season played 4-4-2 and he was a pure winger or left midfielder," he said. "Now he's an attacker with freedom and that freedom gives him a chance to play and a better chance to score."

Chelsea can certainly play better. Villa's five-man midfield helped to stifle their fluency but a first St Stephen's Day win since 1999 was all that mattered. They now have eight wins and two draws from their 10 Premiership home games.

Mourinho knows his team must continue their good form. "It's not our target to be what you call winter champions," he said. "Our aim is to be champions at the end of the season."

Villa's big mistake here was the ease with which they left themselves open to the counter-attack that brought the decisive goal. Robben was allowed to pick up the ball unopposed in his own half and run at a backpedalling defence. He picked out Duff, who cut inside Liam Ridgewell and scored with a low shot.

Villa had started decently. They looked to take the game to Chelsea and the lively Lee Hendrie got into dangerous positions near the edge of the box for shots that came to nothing.

Juan Pablo Angel did a useful job as a lone striker but Villa too often lacked presence in the box and found it hard to make clear chances. They came no closer to an equaliser than long-range efforts by Peter Whittingham and Nolberto Solano.

With Mathieu Berson doing a decent defensive job, even if he was sometimes wasteful with the ball, Villa were rarely overrun. The inexperienced Ridgewell generally did well alongside Olof Mellberg at the back, but Chelsea had openings. Most notably, Mark Delaney cleared off the line from Robben, John Terry headed wide and Thomas Sorensen saved from Eidur Gudjohnsen.

"If you take the goal away there wasn't much in the game," said Villa's manager David O'Leary, who noted that every available member of his squad was involved in the 16 here. The booking that Mellberg picked up means he will miss next weekend's game against Crystal Palace and, with Delaney going off injured, O'Leary has a problem in central defence. "We don't have any more centre backs at the club," he said.

Worries for Villa, but Chelsea roll on. And few would back against Duff shining again at Portsmouth tomorrow.

Guardian Service