Winger Tom Homer guided London Irish to a 25-12 victory over London Wasps to enhance their chances of making the Heineken Cup.
In the battle of two mid-table teams, Homer scored 20 points which included six penalties and a conversion in a perfect kicking display.
All Wasps' points came in the first quarter in the form of tries by Riki Flutey and hooker Rob Webber, but their indiscipline was ultimately their undoing.
With both sides almost certainly out of the play-off picture, it was a battle for European places and Homer kicked Irish into an early three point lead.
However, the away side scored two tries in five minutes. Desperate for their season not to enter the stages of mediocrity, Wasps centre Flutey went over, Walder converting.
They extended that lead further when Webber touched down for an unconverted try. But Homer was on form with the boot and scored two more three pointers to reduce the deficit.
Irish then took the lead through a brace of Homer penalties to leave it 15-12 at the break.
The winger continued where he left off in the first period to extend that advantage in the second with a penalty before the decisive moment in the match.
With 25 minutes left on the clock, hooker David Paice powered over for Irish's only try of the game, Homer converting, And despite Gary Johnson's late sin-binning, Wasps couldn't find a way through further denting their European aspirations and boosting Irish's chances of making next season's Heineken Cup.
For London Irish:
Pens: Homer 6
Tries: Flutey, Webber
London Irish: 15 Delon Armitage, 14 Topsy Ojo, 13 Elvis Seveali'i, 12 Seilala Mapusua, 11 Tom Homer, 10 Daniel Bowden, 9 Paul Hodgson, 8 George Stowers 7 Steffon Armitage, 6 Jamie Gibson, 5 Bob Casey, 4 Nick Kennedy, 3 Faan Rautenbach, 2 James Buckland, 1 Clarke Dermody (c).
Replacements: 16 David Paice, 17 Alex Corbisiero, 18 Paulica Ion, 19 Gary Johnson, 20 Richard Thorpe, 21 Adam Thompstone, 22 Ryan Lamb, 23 Darren Allinson
London Wasps: 15 Mark van Gisbergen, 14 Christian Wade, 13 Dom Waldouck, 12 Riki Flutey, 11 David Lemi, 10 Dave Walder, 9 Joe Simpson, 8 Andy Powell, 7 Will Matthews, 6 John Hart (c), 5 Marty Veale, 4 Simon Shaw, 3 Zak Taulafo, 2 Rob Webber, 1 Tim Payne.
Replacements: 16 Tom Lindsay 17 Charlie Beech 18 Ben Broster 19 Joe Launchbury 20 Dan Ward-Smith 21 Nic Berry 22 Josh Lewsey
Referee: Chris White