Leguizamon's late showboating error did not prevent an Irish win
London Irish 16 (10)
Pens: Everitt, Flutey 2
Wasps 13 (3)
Cons: Van Gisbergen
Pens: Van Gisbergen 2
London Irish edged out Wasps in a thrilling match in front of a record Premiership crowd of almost 23,000.
A late Riki Flutey penalty secured a more than deserved victory for Irish.
Irish were 10-3 up at the break thanks in part to a brilliant try from Topsy Ojo, before Chris Bishay went over to bring Wasps back into the match.
But Flutey's late kick won the day, to the relief of Juan Manuel Leguizamon who missed a certain try by attempting an extravagant celebratory dive.
Leguizamon's error must surely rank as one of the biggest sporting blunders in recent times and clearly angered Irish coach Brian Smith on the touchline.
Smith's side stay in sixth place in the table, but the win strengthens their chances of a top-four finish, while Wasps won't be happy with dropping back from fourth to fifth.
London Irish forwards coach Toby Booth on whether Leguizamon would be buying the drinks:
"As long as he is not carrying them. Juan is quite an emotional character. It's part and parcel of what you get and you don't want to coach that out of people.
"After the game he beat himself up a bit. He is devastated. He is a very proud person and does not want to feel he has let his team-mates down."
Booth added: "It was a big occasion, they are one of the best sides in the country and we showed the inner steel you get from winning."
Wasps coach Ian McGeechan on the 75th-minute penalty against his side:
"We just want a fair crack of the whip. It was a bit harsh.
"Unfortunately we gave them the ball to play with in the first half and made it too easy for them, but we came back well."
London Irish: Flutey; Ojo, Mordt, Mapusua, Tagicakibau; Everitt, Hodgson; Hatley, Russell, Lea'aetoa, Kennedy, Casey (capt), Roche, Armitage, Murphy.
Replacements: Collins, Paice, Hudson, Leguizamon, Magne, Willis, Bishop.
Wasps: Van Gisbergen; Bishay, Waters, Lewsey, Voyce; King, Amor; McKenzie, Ward, Adams, Shaw, Skivington, Hart, O'Connor, Dallaglio (capt).
Replacements: Webber, Bracken, Leo, Birkett, Brooks, Cipriani, Erinle.