Connacht's hopes of topping their European pool to gain automatic qualification into the quarter-finals lost momentum on Friday night when a stronger London Irish proved their credentials of regaining Heineken Cup status.
The visitors, after a poor opening half, grabbed the initiative in the second to post four tries, bag the bonus point, and take leadership of pool one in their determination to use the Challenge Cup as a route to regaining their entry into the top echelons of European rugby.
Connacht were made to pay - firstly for gifting London Irish two soft tries in the first half, and secondly for their failure to finish the try-scoring chances they created.
The scoreline was hardly a fair reflection of their endeavour on the night, but in a tournament that has become increasingly competitive, London Irish demonstrated the domination English premiership sides enjoy in the Challenge Cup.
Their huge physical pack, combined with the speed of their three-quarters, proved a formidable all-round combination that is reflected in their current sixth position in the premiership table - ahead of Sale Sharks who played Munster last evening.
Yet just 12 - 7 down at the break, Connacht had looked the more creative of the two sides. Despite an erratic line-out and a creaking scrum, they had stymied a London Irish outfit that too often kicked poorly and failed to create anything with the possession they had. John Muldoon and Johnny O'Connor made a statement in front of Irish coach Declan Kidney in continuing their outstanding form, aided and abetted by Ray Ofisa in the back row. Ian Keatley once again kicked intelligently, while Fionn Carr was at the heart of Connacht's most creative efforts. Weather, of course, played its hand once again at the Sportsground, and it was Connacht who faced into the wind and rain in the opening half. But they contributed to their downfall when Irish posted 12 points by the 14th minute. The first try came courtesy of a free after Connacht scrumhalf Frank Murphy delayed his put-in against a wheeling scrum. When Irish hacked the ball down field, fullback Fionn Carr did wel under pressure to claim possession, but after the big Irish pack drove over - off their feet - they quickly fed it out wide and it was Elvis Seveali'i who crossed after nine minutes.
If that was a soft try, their second five minutes later was a gift. Connacht, putting in the hard yards and going through the phases, were camped on the visitors' line when the ball was spun from left to right. Right wing Liam Bibo did well to control possession, but his attempted pass inside to Carr spilled forward, and England winger Topsy Ojo took advantage. Breaking out down the blind side, he found a willing Seilala Mapusua who was able to run in the 10m line untouched.
It was a sickening blow for the home side, but to their credit their response was rapid, and when Murphy made the incisive break up the blind, he found support in Bibo who supplied Carr for the finish. Ian Keatley added the extras to reduce the arrears.
The visitors, however, came out fighting early on the resumption. Flanker Steffon Armitage set up the try with a break from a penalty kicked to touch, and Connacht, having stopped No 8 Chris Hala'Ufa just shy of the line, missed a couple of first-up tackles as the ball was spun wide and Ojo had an easy run-in from 10metres out.
Peter Hewat added the conversion, and although Connacht pegged back the lead with a 53rd minute penalty, the London Irish outhalf cancelled that effort on 66 minutes.
Connacht did have their chances. Carr, who had chinked inside and out of three defenders, came closest, but put a foot in touch just a yard from the line. Minutes later Ray Ofisa broke from the loose, but his attempted pass to a supporting Brett Wilkinson was knocked forward from Irish outhalf Peter Hewat.
Unable to finish those efforts, the game's complexion changed with a host of replacements and front row injuries, which necessited uncontested scrums. As a result Connacht lost their shape, and fell into a tit-for-tat kicking game. Irish, with the superior counter-attacking skills, capitalised, and Ojo added his second to ensure Irish take pole position in the pool, with another bonus point.
Connacht: F Carr, L Bibo, G Duffy, A Wynne, J Hearty, I Keatley, F Murphy, B Wilkinson, S Cronin, R Morris, M Swift, A Farley, R Ofisa, J O'Connor, J Muldoon (cpt ). Replacements: R Loughney for Morris 53m, S Cronin for Flavin 55m, R Morris for Wilkinson 58m, A Browne for Swift 60m, C Rigney for Morris 66m, A Dunne for Hearty 68m, T Nathan for Muldoon 74m, K Campbell for Murphy 76m.
London Irish: D Armitage, T Ojo, E Seveali'i, S Mapusua, S Tagicakibau, P Hewat, P Hodgson, A Corbisiero, J Buckland, T Lea'aetoa, N Kennedy, B Casey (cpt ), R Thorpe, S Armitage, C Hala'Ufia.
Replacements, C Dermody for Lea'aetoa 41m, D Paice for Buckland 53m, F Rautenback for Corbisiero 53m, D Danaher for Thorpe 57m, G Johnson for Rautenbach, S Geraghty for Seveali'i 65m.
Referee: J Garces (France ).