Chelsea 2 Portsmouth 0: Mourinho's tactical nous lifts Chelsea

Slick switches are rewarded by Lampard and Robben

Peeved he may have been by the midweek defeat against Barc-elona, which seriously threatens the Champions' League triumph he has been craving these past 12 months, but Jose Mourinho earned his roubles again yesterday.

His first substitution was made after only half an hour, when Asier Del Horno's bad week took an even worse turn as he was ruthlessly hauled off for Damien Duff; Chelsea immediately roused themselves and finally scored the goals required for a routine victory following a further double change that brought on Eidur Gudjohnsen to create both of them.

Ordinary as the champions had been until that point, a 15-point lead at the top of the table is the outcome, while Portsmouth's eight successive away defeats tell a relegation tale. They have never scored a goal against Chelsea in six Premiership matches and are highly unlikely to have the chance to do so next season. It was easy to imagine the rueful tone of the conversation between the respective clubs' Russian owners in the posh boxes afterwards.

Roman Abramovich has had more stimulating days at the Bridge - many of them. After the draining drama of last Wednesday night, it was understandable that both the home team and the atmosphere were flat - flatter, certainly, than the playing surface. Anticipating that, Mourinho tried to freshen up his side with four changes, restoring Michael Essien, Shaun Wright-Phillips, Robert Huth and Didier Drogba, but to limited effect. Hence the unusually early change of tack and tactics on a pitch that, far from being freshened up, looked drier and more scuffed than ever, hindering what few constructive passing moves there were in a dull opening.

Chelsea, predictably, put together most of them, Wright-Phillips causing the first shudder in the visitors' ranks with an angled shot from just inside the penalty area that Dean Kiely needed two grabs to repel. But Mourinho's high standards were not being met, and after twice bawling out Del Horno he pulled the full-back off, even earlier than he had been sent off in midweek. Duff's arrival, albeit in an unfamiliar position, had the desired effect of livening his side up. His first touch was a square pass for Wright-Phillips, who shot too high. A couple more minutes and John Terry met Arjen Robben's curling free-kick from the right with a smart header that Kiely did well to parry. The goalkeeper next had to beat out a direct free-kick by Drogba before holding Huth's weaker header from the rebound.

Early in the second half, Kiely was required to make another save as Wright-Phillips shot from 20 yards, Frank Lampard for once getting no power on the follow-up. Mourinho was soon twitching again, risking his two remaining substitutions on the hour and finding fortune favouring his bravery. Gudjohnsen and Claude Makelele, left out after Wednesday's exertions, replaced Wright-Phillips and Joe Cole, and within six minutes the Icelander was instrumental in forcing a goal.

Drogba, on the left, laid the ball towards Gudjohnsen, who deftly stepped over it, allowing Lampard to come steaming through and shoot low inside a post for his 17th goal of the season. Even Kiely could not keep that one out.

Cursing his nephew, Harry Redknapp responded by sending on Wayne Routledge, the little winger who has been in indifferent form since joining on loan from Tottenham. It was a good move to pit him against Duff, the irregular left-back, and when Routledge went past the Irishman with ease, his cross was only fractionally too far ahead of Richard Hughes, who could only head wide.

The danger, of course, was Chelsea's speed on the break, not entirely negated by the pitch. Twelve minutes from time Gudjohnsen lobbed a pass over the two central defenders for Robben to open his body and side-foot carefully past Kiely. Drogba, Lampard and Paulo Ferreira all missed the target in the last few minutes, though neither side deserved a rout.

"I never felt we were under any real pressure," said Redknapp, who needs to look on the bright side these days. "It's going to be tough, but we always knew that. There's 11 games to go and points to play for. But it's been one of those weeks." Del Horno knows the feeling.