Former England fly-half Alex King came off the bench to snatch victory for Wasps with a 79th-minute drop goal.

King had only been on the pitch for six minutes when he made the most of his first touch of the ball by landing an opportunist left-footed match-winner from 35 metres.

His crucial kick, followed by an injury-time penalty from full-back Mark Van Gisbergen, who contributed 17 points, robbed Rikki Flutey and Topsy Ojo of a fairytale debut for Irish.

It looked as though they had struck the telling blows when England Under-21 winger Ojo, a 40th-minute replacement for the injured Justin Bishop, showed an electrifying burst of speed to chase a kick from full-back Delon Armitage to touch down.

That levelled the score at 24-24 in the 71st minute with Flutey adding the conversion to edge Irish 26-24 ahead.

But Wasps hit back to have the final say.

Flutey turned in a 100 per cent kicking display to contribute 16 points after only being handed a place in the starting line-up 20 minutes before the kick-off.

The 25-year-old new signing, who arrived from New Zealand last Monday, was promoted from the bench when fly-half Barry Everitt sustained an ankle injury during the pre-match warm-up.

The former Wellington Hurricanes player responded with six kicks from six attempts - four penalties, including one from just inside the Wasps' half and one from the right touchline, and two conversions.

His first came in the seventh minute after centre Shane Geraghty caught the Wasps defence napping.

The visitors stood still as Geraghty appeared to slip, spun through 360 degrees as he recovered, and ran unchallenged to touch down between the posts.

But Wasps stayed in touch as Van Gisbergen marked his call-up by England coach Andy Robinson with his own near-perfect goal-kicking performance.

The New Zealand-born full-back, who only recently qualified for England selection, landed six from seven attempts, with five penalties and a conversion.

Trailing 16-12 at the interval, after their lineout misfired badly in the first half, Wasps went ahead for the first time in the 46th minute.

Their adventurous approach in electing to choose a scrum instead of a penalty kick paid off in the 46th minute when scrum-half Eoin Reddan spun off the back of the set-piece to dive over by the left corner flag.

Van Gisbergen failed with the conversion attempt, his only miss of the afternoon.

Flutey restored the Irish lead with his fourth penalty before Wasps went ahead with their second try in the 52nd minute.

Their former London Irish right-winger Paul Sackey, playing against his old club for the first time since his transfer last season, was felled by a crunching tackle from Armitage.

And this time it was Irish who were left standing as the ball bounced loose.

Wasps flanker Jonny O'Connor picked it up and ran in unchallenged from 25 metres, with Van Gisbergen converting to put Wasps 24-19 ahead.

There were still two twists in the tale with Ojo and Flutey restoring the Irish lead, before King and Van Gisbergen had the final say.