CHELSEA moved 15 points clear at the top of the Premiership thanks to a 2-0 win over Portsmouth at Stamford Bridge. Frank Lampard and Arjen Robben were the men on target in the second half but it had hardly been a scintillating display from Jose Mourinho's men. However, the result pushes Pompey deeper into relegation trouble.

Shaun Wright-Phillips won an early corner but Robben's cross was headed over by John Terry. Lomana LuaLua responded by winning a corner at the other end but it resulted in nothing more than a tame, 25-yard effort from Ognjen Koroman that bobbled harmlessly wide.

Didier Drogba needed treatment after he was flattened by Andy O'Brien just outside the Pompey penalty box in a collision but referee Mike Riley decided had been accidental.

The striker was soon able to rejoin the game but Chelsea were already having trouble stringing meaningful passes together despite enjoying almost all the possession. Wright-Phillips won another corner and Robben twice saw shots blocked. The Dutchman then fired a snapshot wide before Pompey forced two corners in quick succession.

Robben had another go with the ball flying just inches over Dean Kiely's crossbar. Mourinho had already decided on a change however, and Damien Duff replaced Asier del Horno in only the 31st minute. Immediately a chance came Wright-Phillips' way but the former Manchester City man's shot was also too high.

Kiely was required to make his first save of the afternoon in the 33rd minute when Terry met Joe Cole's freekick with a header from five yards out. Wright-Phillips flashed a ball across the box from the right that eluded first Robben at the near post and then the outstretched leg of Drogba at the far.

Pedro Mendes tried to chip Petr Cech from 30 yards but realised he had not hit it sweetly enough and the ball bounced harmlessly wide.

The former Porto man, who had won a Champions League winners' medal there under Mourinho, soon had another go but this one was high as well as wide.

Mourinho made two more changes on the hour, with Cole and Wright-Phillips discarded in favour of Eidur Gudjohnsen and Claude Makelele. It worked as Lampard stroked Chelsea ahead in the 65th minute, having accepted a pass from Drogba that Gudjohnsen allowed to run into his path. The England man was a yard inside the box and sent a low drive beyond Kiely.

Mendes fired an effort only just over before Sean Davis replaced Richard Hughes in the 73rd minute. BUt it made no difference and Robben made sure of the points with the second goal 12 minutes from time, slotting past Kiely after Gudjohnsen's ball over the top had put the Dutchman clear.

LuaLua was booked for dissent before Paulo Ferreira poked a late Chelsea chance across goal and wide.