Pompey boss Velimir Zajec has told his players to bounce back from a third successive Premiership defeat - by knocking Saints out of the FA Cup.

Two-goal Didier Drogba and a second against Pompey in as many games from the brilliant Arjen Robben gave Chelsea a seventh successive win.

Meanwhile, Pompey's miserable 2005 continues but Zajec reckons Saturday's FA Cup fourth-round tie at St Mary's will provide a welcome distraction from the club's Premiership struggles.

He said: "Saturday is the big game. We are disappointed but Chelsea are a good side and now we have to move on and make sure we win against Southampton.

"That's the match that everyone wants to win. Staying in the Premiership is our priority but we all know how much this game means to the supporters."

It is only a month since Pompey excelled in a 1-0 defeat against Chelsea at Fratton Park, where Robben's deflected winner was rough justice on the home side.

But only five of that side started at Stamford Bridge because of two injuries, two suspensions, the sale of Nigel Quashie - and an illness to captain Arjan De Zeeuw.

De Zeeuw was sick several times on the bus to west London - and was withdrawn from the starting line up after throwing up in the away dressing room.

But Chelsea would have beaten most teams in Europe on their first-half showing.

Drogba scored the first with a 15th-minute tap-in after Robben had skipped past Gary O'Neil and David Unsworth.

Then Robben rounded Jamie Ashdown to double the lead in the 21st minute after latching on to a through-ball from Frank Lampard that was weighted to perfection.

Drogba completed the blitz by curling a 39th-minute free kick past Ashdown. It was game over and a third successive Premiership defeat for Pompey.

It might have been a little different if Yakubu had pulled a goal back when, with the score at 2-0, he missed the target after an uncharacteristic Lampard mistake had put him clean through.

Gary O'Neil forced Petr Cech to tip over his 48th-minute free kick, but that was the Chelsea number one's only significant save.

Pompey looked lacklustre but coach Joe Jordan refused to admit that the club could be sucked into a relegation battle, despite a third successive Premiership defeat and a lead over third-from-bottom Saints that has been cut to nine points

"The players were very down afterwards and because they felt that way I'm not thinking about a relegation battle," he said.

"We have always said our target for the season is 40 points, ever since our first game against Birmingham in August, but it doesn't look like we'll need as many this year."

Jordan preferred to praise Chelsea's widemen - but insisted that the Premiership race is far from over.

"We felt a little bit hard done by against Chelsea at Fratton Park but this time Robben and Duff were too much for us.

"The two of them made it difficult for us by coming into the middle of the park and looking for the ball, and I don't think anyone works as hard as Damien Duff.

"But I don't believe it's over yet, it's not as straightforward as that. I'd like to think this league is the most competitive in the world.

"There's a lot at stake and this club hasn't won a championship for 50 years - it's still got to be won."