Elissalde crossed for the crucial try near the end
London Irish (8) 24
Tries: D Armitage 3, Geraghty
Cons: Everitt 2
Toulouse (12) 26
Tries: Garbajosa 2, Baby, Elissalde
Cons: Courrent, Elissalde 2
London Irish crashed out of the Heineken Cup after a narrow defeat to Toulouse at the Madejski Stadium.
The Exiles scored four tries, including a hat-trick for full-back Delon Armitage, but still found themselves on the wrong end of the close scoreline.
Shane Geraghty also crossed for a try, but scores from Jean-Baptiste Elissalde and Benoit Baby punished the Exiles.
Armitage struck three times in the last 15 minutes but the home side should have wrapped it up earlier.
London Irish started off with a willingness to throw the ball around but Jean-Frederic Dubois angled the ball through an overworked defence for Xavier Garbajosa to dive over for Toulouse's opening score.
Home flanker Olivier Magne lost the ball on halfway and second row Gregory Lamboley broke clear to put Garbajosa in again just 10 minutes later.
London Irish came up short at the Majedski Stadium
Seilala Mapusua should have done better when a brilliant Geraghty pass put him into space with men outside, but the centre opted to take contact instead and the chance went begging.
With Garbajosa in the sin-bin for taking out Paul Hodgson, London Irish picked up from the back of the scrum and Geraghty showed good strength to go through Gareth Thomas' tackle and score just before the break.
Armitage grabbed his first on 65 minutes with Geraghty and Tonga Lea'aetoa working him into space for a clear run to the line.
The full-back landed his second soon after thanks to a weaving run from Topsy Ojo.
And another sin-binning for Toulouse - with Gregory Lamboley in trouble - should have given the home team the chance to clinch the win.
But the Exiles switched off and Thomas cut through in midfield before floating a pass to Baby.
Toulouse's fourth try, coming from a turnover in Exiles territory, came from Elissalde, to render Armitage's injury-time hat-trick try meaningless in terms of the result.
London Irish coach Brian Smith:
"If you tighten up and don't try to take Toulouse on, you'll end up losing.
"This was a chance to take on one of the great European teams.
"We probably had a 60-40 advantage in terms of chances created and in better conditions with better handling we would have won the game."
London Irish: Armitage; Ojo, Tiesi, Mapusua, Shabbo; Geraghty, Hodgson; Lea'aetoa, Coetzee, Rautenbach, Kennedy, Casey (capt), Roche, Magne, Leguizamon.
Replacements: Skuse, Paice, Hudson, McCullen, Flutey, Rees, Everitt.
Toulouse: Thomas; Garbajosa, Kunavore, Baby, Medard; Dubois, Courrent; Human, Lacombe, Hasan, Lamboley, Brennan, Bouilhou (capt), Montauriol, Maka.
Replacements: Servat, Perugini, Millo-Chluski, Nyanga, Elissalde, Mermoz, Huget.