Jimmy Floyd Hasselbaink rediscovered his scoring touch and Enrique de Lucas popped up with a goal, but a late header from Ben Wright ensured that Viking Stavanger's hopes are very much alive in this Uefa Cup first round tie.

Normally so prolific, Hasselbaink had failed to score this campaign and his partnership with Eidur Gudjohnsen has yet to reproduce last season's fireworks.

But the Dutch international striker looked back to his best when he picked up Jesper Gronkjaer's deflected shot and scored from an acute angle.

De Lucas looked to have made the tie safe for Chelsea but then Englishman Wright stole a vital away goal in the dying moments.

Early on Hasselbaink had set the tempo for Chelsea, his astute pass carving open the Viking defence, but Olsen did well to clear Gronkjaer's low shot.

Soon after the Dane created his own shooting opportunity, coming inside and again forcing Olsen to make a reaction save.

After displaying his shooting and deft footwork, Gronkjaer then demonstrated his vision, picking out Jody Morris, only for the midfielders' first touch to let him down.

In the half's closing moments the Dane again came to the fore when he delivered a low cross, which somehow eluded William Gallas, Hasselbaink and Gudjohnsen.

Gronkjaer's speculative shot led to the goal.

The Dane's effort ricocheted off Brede Hangeland and Hasselbaink snaffled up the rebound.

De Lucas doubled Chelsea's advantage, collecting Jody Morris' chip, before lobbing Olsen.

Over the last two years Chelsea have made early exits from the Uefa Cup against unfancied Hapoel Tel Aviv and Switzerland's St Gallen.

And Viking also managed to intermittently unnerve a Chelsea defence missing John Terry, who is recovering from knee surgery, as well as the injured Graeme Le Saux, Celestine Babayaro, Albert Ferrer, and Mario Melchiot.

Trygve Nygaard was allowed to test Cudicini with a half-volley, and Erik Nevland almost sent Tom Sanne clear.

Peter Kopteff's pace and skill on the left also provided an important outlet for the Norwegians.

And it was from Kopteff's cross that Wright headed his potentially crucial goal.

Chelsea: Cudicini, Stanic, Gallas, Desailly, Huth, Gronkjaer, Morris, De Lucas, Zola, Gudjohnsen, Hasselbaink.
Subs: de Goey, Lampard, Zenden, Ambrosetti, Oliveira, Kitamirike, Keenan.

Viking FK: Olsen, Dahl, Hangeland, Kuivasto, Pereira, Fuglestad, Sanne, Nygaard, Kopteff, Berre, Nevland.
Subs: Nordtun, Espevoll, Berland, Ahmed, Sorli, Sigurdsson, Wright.

Referee: Ben Tokat (Turkey).