The duo both took advantage of unmarked positions to send the majority of a Saints club record crowd of 31,107 home from the new 32m St Mary's Stadium disappointed.

Three points on their travels is no mean feat for the Blues, who endured a woeful time away from Stamford Bridge in the last campaign.

Claudio Ranieri's men lost 3-2 at the Dell in season 2000-01, but still have won five of their last eight league meetings in Southampton.

The hosts deserved more on their big day and could have had a penalty late on when Blues centre-back John Terry seemed to clip James Beattie just inside the box on the left, but referee David Elleray pointed for a goal-kick rather than one from the spot.

The mutterings that Saints will struggle without the Dell are, of course, well under way. With that in mind, Southampton, without injured skipper Jason Dodd, began like a side determined to disprove the doubters.

The best offering of an extended period of early pressure fell to Kevin Davies as Chelsea made a hash of clearing their six-yard box, but the striker's half-flick was gratefully gathered by Ed de Goey.

The afternoon heat seemed to drain the game of inspiration and genuine chances before the break were few, though Anders Svensson managed a shot just over de Goey's bar.

Hasselbaink had been limited to a weak header and a sliced 20-yard shot before his decisive strike. The move began when the quiet Emmanuel Petit swapped passes with Graham Le Saux, whose pin-point cross from out wide left Paul Jones grasping at thin air. Hasselbaink simply couldn't miss.

Saints declined the opportunity to reply immediately as Davies, played in by Uwe Rosler, clipped his shot wide of the far post.

The second half was rather more frenetic, though Petit's contribution lasted just four minutes; the Frenchman limped off with a suspected hamstring pull to be replaced by Jody Morris.

Frank Lampard did well to block Anders Svensson's sharp shot as Saints turned up the pace. Rory Delap fired a 25-yard free-kick just over the bar and Rosler twice threatened with headers.

Chelsea, for whom Jody Morris cracked a shot just over, were largely prepared to soak up the pressure but Matt Oakley sliced his shot from just outside the box wide of the right upright in stoppage time.

Gianfranco Zola almost had a goal on the break, but the Italian hit across goal when Hasselbaink was poised at the back post eager to double his tally.