With Sale, Worcester and London Welsh all losing this weekend, the Exiles knew a win would give them some room at the bottom of the table and they put on a fine display to keep the high flying Wasps at bay most of the game.
They dominated the breakdown while surging runs from Chris Hala’ufia and Oscar Treviranus to put Wasps under huge pressure but their discipline let them down to invite their close neighbours back into the game.
But the issues were addressed at the break and Brian Smith’s players controlled most of the second half against a Wasps’ side who seemed to have lost their recent spark of late.
As a result, the Exiles overtake London Welsh in the table to be five points clear of Sale who are still rock bottom.
Wasps had a late charge trying to secure a losing bonus-point but couldn’t do so and remain in fifth position behind Gloucester on same points.
The home side were off to a very good start when, from the kick off, Shane Geraghty chased hard and put pressure on Sam Jones to earn a penalty for the Exiles.
Tom Homer hit the post but, two minutes later, he was successful from 25 yards to put the home side 3-0 in front.
The first ten minutes were all about Brian Smith’s men but Wasps’ defence kept them out on two occasions.
First prop Halani ‘Aulika was held-up following a well-worked catch and drive and, from the resulting scrum, Marlan Yarde was tackle into touch inside the in-goal by Christian Wade.
Homer doubled the lead on 15th minute but Wasps eventually got their hands on the ball and got on the scoreboard five minutes later when Stephen Jones kicked a penalty to reduce the gap.
But this reaction didn’t derail the Exiles’ train and two minutes later they earned another penalty 10 metres in front.
Homer looked set to kick his third penalty but Ian Humphreys saw the defence was walking towards the posts and tapped the ball quickly to send Geraghty over in the corner for a deserved 11-3 lead.
Jones reduced the gap with two penalties in quick succession before Wade showed some great feet in confine space to score at the end of great move initiated by Ashley Johnson and Sam Jones.
But Wasps conceded another penalty soon after and Homer reduced the gap to only trail 14-16 at the break.
From the restart, Exiles’s bad boy Chris Hala’ufia was sent to the bin for leading with his elbow into the face to T Rhys Thomas and Jones kicked the resulting penalty to extend the lead.
Homer reduced the deficit and as Hala’ufia came back onto the pitch and he went from zero to hero initiating a superb try.
The Tongan No.8 found some room out wide before offloading to Oscar Treviranus who then found Yarde on the switch to send the young winger over the line.
Homer kicked the conversion before slotting his fifth penalty of the game and the Exiles were leading 27-19.
Wasps threw everything they could to score again but the improved Exiles defence managed to keep them out and close the game down with Homer adding a penalty for good measure to round-up his superb kicking display.
For London Irish
Tries: Geraghty, Yarde
Penalties: Homer 6
Sin bin: Hala’ufia
For London Wasps
Conversion: St Jones
Penalties: St Jones 4
London Irish: Homer; Ojo, Armitage, Geraghty, Yarde; Humphreys, Phibbs; Lahiff, Lawson, Aulika; Skivington, Evans (Capt.); Garvey, Treviranus, Hala’ufia.
Replacements: McGregor, Yanuyanutawa, Halavatau, Low, Gibson, Fisher, Tagicakibau, Moates.
London Wasps: Southwell; Wade, Daly, Bell, Varndell; St. Jones, Simpson; Taulafo, Thomas, Taylor; Cannon, Wentzel; Johnson, Poff, Sa. Jones.
Replacements: Lindsay, McIntyre, Romano, Rae, Everard, Davies, Robinson, Hayter.
Referee: Tim Wigglesworth
Star man: Chris Hala’ufia – London Irish
You can relive all the action from the Madejski here.