All Blacks centre Sam Tuitupou marked his Guinness Premiership debut with a top quality try but it was not enough to give Worcester Warriors their first league victory of the season.

Irish snatched victory with three minutes to go when winger Sailosi Tagicakibau scored a breakaway try in the left-hand corner, converted by full-back Delon Armitage.

Even the losing bonus point which Worcester secured at the fog-shrouded Madejski Stadium by keeping the margin of victory to seven points wasn't enough to lift them off the bottom of the table ahead of fellow strugglers Leeds Carnegie.

Prop forward Richard Skuse scored the other Irish try with Armitage landing three penalties and two conversions for a personal contribution of 13 points.

The other Worcester points came from the boot of fly-half Shane Drahm who converted Tuitupou's try and also landed three penalties.

All eyes were on Worcester's big name signing Rico Gear but the New Zealand winger had little chance to show his dangerous attacking attributes and it was his fellow Kiwi Tuitupou who looked like sealing the honours until Irish snatched victory at the death.

Taking an inside pass from Drahm, Tuitupou, capped nine times by New Zealand, left the Irish defence standing as he burst through the middle for his 46th-minute try.

That put the Warriors 13-10 ahead and raised hopes that they would finally break their Premiership duck at the eighth attempt.

Armitage edged Irish back in front with penalties in the 53rd and 63rd minutes only for Drahm to level the scores at 16-16 two minutes later.

In the first half Irish got off to a flying start, going 7-0 ahead after only four minutes.

Flanker Steffon Armitage - Delon's brother who was called up to replace Kieran Roche, out with a nasty eye injury suffered in last weekend's Heineken Cup defeat by Perpignan in France - was held up just short of the Warriors line in the third minute.

A minute later, England scrum-half Peter Richards was stopped a metre short of the line but, from the resulting drive, Skuse forced his way over for a try converted by Delon Armitage.

Drahm and Armitage exchanged penalties before Worcester lost hooker Aleki Lutui to the sin-bin in the 34th minute.

Lutui, who had just conceded the penalty to Irish, immediately infringed again by taking out a home player at the restart and referee Ashley Rowden had no hesitation in brandishing the yellow card.

But Irish were also reduced to 14 players in the 40th minute when Delon Armitage was yellow-carded for cynically sticking out a leg and impeding Marcel Garvey after the Worcester left winger chased his own kick as the ball bounced over the tryline.

Drahm kicked the resulting penalty to reduce the London Irish lead to 10-6 at half-time.

Irish, forced to make a late change and bring in Shane Geraghty at fly-half after England veteran Mike Catt failed a morning fitness test on his problem back, had the better of the first half.

Their forwards denied the Worcester pack the chance to create a platform to unleash the attacking skills of new signings Gear and Tuitupou until the centre scored his excellent second-half try.

The only threat from Gear came when he tried a kick and chase down the right wing but the danger was easily cleared.

Worcester had looked well in the game until the home side claimed the deciding score late on.