Toby Booth insists his young London Irish team will benefit from this season's Heineken Cup adventure, despite seeing their hopes of qualification ended at Madejski Stadium.

Exiles lost all three home games in their pool and cannot progress to the quarter-finals regardless of how they get on in their final match at Edinburgh next Sunday.

The only try of the game by Cardiff's outstanding back-row forward Sam Warburton turned the game in the Welsh region's favour, although there seemed to be a knock on earlier in the move that was missed by referee Neil Paterson.

Booth said: "There was one key moment in the game from which they scored a try and that proved to be decisive.

"Both teams defended very well. It was a tight game and that has been the story of the Heineken Cup in this group.

"I am not disappointed with the effort, just the outcome.

"We have been in every contest and maybe it will be good for the evolution of London Irish.

"This new group of players has not played much in the Heineken Cup and will be better for the experience.

"That does not hide the disappointment of where we are now."

London Irish's head coach continued: "When you are putting out youngsters you have to take the error count that comes with it.

"They are very talented, but executing under pressure is all part of the evolution of players.

"I thought David Sisi and Alex Gray in the back row were outstanding.

"Their effort was excellent and they will learn a massive amount from that game.

"Darren Allinson was absolutely first class in how he managed the game at 9 in what was a 50-50 battle in a lot of elements.

"Up front Matt Garvey again showed his credentials and certain other players are stepping up to the plate.

"It was a tight game and unfortunately we have come out the wrong side of it.

"We need to learn our lessons and become a bit more street-wise regarding the difference between Heineken Cup and the Premiership.

"There is no masking our disappointment regarding the outcome of the campaign, but ultimately the squad will be better for it."

Exiles hit back after Cardiff full-back Leigh Halfpenny had opened the scoring in the seventh minute with the first of his five penalties.

Fly-half Adrian Jarvis slotted over three penalties to give Irish a 9-3 lead only for Halfpenny to reduce the deficit with the last kick of the half.

And Cardiff seized the initiative after the break when Warburton went over after producing good support to an excellent break down the left by centre Casey Laulala.

Although Halfpenny did well to land the conversion, Irish hit back quickly with a fine long-range penalty from Delon Armitage to trail 13-12.

Halfpenny and Jarvis then traded penalties, leaving the game in the balance at 16-15 with just over a quarter of an hour remaining.

But two further penalties from Halfpenny, who finished with 17 points, gave Cardiff the win despite a last-minute yellow card for Bradley Davies for deliberately preventing a quick tap penalty.

Click below to see how the game unfolded

London Irish: 15 Delon Armitage, 14 Topsy Ojo, 13 Jonathan Spratt, 12 Shontayne Hape, 11 Adam Thompstone, 10 Adrian Jarvis, 9 Darren Allinson; 1 Clarke Dermody (c), 2 David Paice, 3 Faan Rautenbach, 4 Nick Kennedy, 5 Matt Garvey, 6 Bryn Evans, 7 David Sisi, 8 Alex Gray.
 
Replacements: 16 James Buckland, 17 Alex Corbisiero, 18 Paulica Ion, 19 Bob Casey, 20 James Sandford, 21 Tom Homer, 22 Steven Shingler, 23 Paul Hodgson.

Cardiff Blues: 15 Leigh Halfpenny, 14 Alex Cuthbert, 13 Casey Laulala, 12 Gavin Henson, 11 Chris Czekaj, 10 Dan Parks, 9 Lloyd Williams; 1 Gethin Jenkins, 2 T Rhys Thomas, 3 Taufa'ao Filise, 4 Bradley Davies, 5 Paul Tito (c), 6 Michael Paterson, 7 Sam Warburton, 8 Xavier Rush.

Replacements: 16 Ryan Tyrell, 17 John Yapp, 18 Scott Andrews, 19 Ma'ama Molitika, 20 Josh Navidi, 21 Richie Rees, 22 Ceri Sweeney, 23 Richard Mustoe.