Jose Mourinho may describe himself as the conductor of an orchestra, but the Chelsea boss still has several virtuoso soloists in his ranks - and none more so than Arjen Robben.

While John Terry and Frank Lampard surely lead the rankings for player of the season, Robben, who turns 21 tomorrow, has the class to light up any occasion.

He inspired Chelsea to victory against Portsmouth well before half-time at Stamford Bridge as the Blues extended their lead at the top of the table to 11 points.

Having resisted the temptation to go down after being fouled, he crossed for Didier Drogba to score Chelsea's first before hitting the target himself shortly afterwards.

Drogba scored his second goal of the game before half-time, converting a free-kick won by Robben, and the Dutchman was deservedly given a standing ovation when he was substituted late on.

By that stage, Portsmouth were well out of it, with Aiyegbeni Yakubu having wasted their only real chance at 2-0 down.

With next week's FA Cup opponents Southampton having earlier beaten Liverpool, this was hardly a good day for the visiting fans.

Chelsea, however, simply go from strength to strength.

While Arsenal could yet reduce the gap back to 10 points by defeating Newcastle tomorrow, it is now almost impossible to see the Blues self-destructing with just 14 games left.

Portsmouth may have made the early inroads, with Matthew Taylor's cross-shot saved by Petr Cech, but Chelsea were untroubled and simply waited for their moment to pounce.

That took just 14 minutes, although they were indebted to some excellent refereeing by Mike Riley, who ignored his assistant's well-intended flag for a foul on Robben as he sped past Gary O'Neil.

The Dutchman, who was accused of diving at Tottenham last weekend, rode the mistimed tackle and cut the ball back invitingly for Drogba to sidefoot home from close range.

Six minutes later, Chelsea already had victory in their grasp as Robben turned goalscorer himself.

Lampard played a skilfully-weighted ball through for the Dutchman to chase onto and, with recalled goalkeeper Jamie Ashdown rather slow off his line, Robben skipped around him via a deflection.

Even though the ball almost reached the byline, the Chelsea winger maintained the poise to clip the ball inside the post from a tight angle.

Given that Chelsea had conceded just eight goals in their previous 23 league games this season, the chances of a Portsmouth comeback were slim, to put it mildly.

Indeed, the visitors squandered their only chance of a route back into the game after Lampard's careless pass left Terry under pressure from Yakubu.

The Nigeria international, who is linked with a potential move away from Fratton Park, clipped the ball past Terry and bore down on goal, beating Cech but seeing the ball roll inches past the post.

Woe betide any side that fails to take such a golden chance against Chelsea. That was as near as Portsmouth came to making a game of it.

Just two minutes later, Robben was up-ended in full flight on the edge of the penalty area by David Unsworth and Drogba struck a fierce free-kick past Ashdown to make it 3-0. That was game over.

The second half was something of a procession, with Mourinho removing Drogba, Damien Duff and Robben from the fray, but showing his strength in depth as Eidur Gudjohnsen, Mateja Kezman and Tiago came on.

O'Neil did strike a 20-yard free-kick that Cech tipped over the bar, but it was Chelsea who came closer to extending their lead.

Joe Cole shot straight at Ashdown as he stretched to reach Duff's cross, while Kezman shot just past the far post and Lampard also threatened.

Chelsea won at a canter and that should be as worrying for Arsenal and Manchester United as it was for Portsmouth.

Teams

Chelsea Cech, Paulo Ferreira, Gallas, Terry, Bridge, Lampard, Makelele, Cole, Robben (Kezman 75), Drogba (Gudjohnsen 65), Duff (Tiago 67).

Subs Not Used: Cudicini, Jarosik.

Goals: Drogba 15, Robben 21, Drogba 39.

Portsmouth Ashdown, Cisse, Primus, Stefanovic, Unsworth (Mezague 54), Kamara, O'Neil, Hughes, Taylor, Berger, Yakubu (Fuller 65).

Subs Not Used: Hislop, De Zeeuw, Curtis.

Att: 42,267

Ref: M Riley (W Yorkshire).