To lose to Toulouse is no crime, and Leinster could justifiably take heart from a predictably much improved performance at Donnybrook. But gnawing away at them on Saturday evening was the nagging feeling that this was one that got away.

Sure, there was a general feeling that Toulouse were a class act, often in cruise control. There was also a feeling that the Frenchmen under-performed. Yet this perhaps does a disservice to Leinster. Their pressure defence was often excellent, epitomised by Trevor Brennan who put his body on the line like only he can, and so Toulouse were both shaken and stirred.

Manager Jim Glennon had said Leinster had a chance, but that they'd need everything to be right. In the event, it would only have needed a few things to go right.

"Whether there was a general over-estimation of Toulouse," he said later, "or more likely an under-estimation of ourselves - which I think is one of the cardinal sins of Irish rugby - I would suggest that we under-estimated ourselves."

In the first quarter, Toulouse, dishevelled by Christophy Dey laud's departure with a recurrence of his knee trouble (courtesy of Brennan's thumping tackle), were over-elaborate, error-prone and couldn't get a foothold on the game.

That was Leinster's chance to establish some sort of platform and put Toulouse on the back foot. But, leading 6-0, they opted for a left-handed touch-line penalty which the left-footed Alan McGowan missed.

More pressure defence forced Michel Marfaing to screw the ball over the touch-line and should have led to a relieving throw-in. Instead, the generally impressive referee, Chris White, gave Toulouse the throw-in, from which Marfaing's try not only settled them but put them ahead.

Leinster promptly repeated the mistake of opting for another missed McGowan penalty from the left touch-line. Mike Ruddock later bemoaned not having a mobile phone connection to someone on the far side from his seat in the stand.

By contrast, the Toulouse coaching staff, situated on the touch-line, were within earshot of their players, and were able to tell them to opt instead for a short kick to touch from which Belot tapped down and Begue burrowed over. Instead of possibly and deservedly leading by the break, say, 13-7, Leinster trailed 14-6 and were playing catch-up.

They did it well. Alan McGowan, who generally varied his game well from a cautious start to a more expansive approach, provided the moment of the match when he took David O'Mahony's tap penalty inside half-way and carved through to score under the posts to bring Leinster to within a point.

Alas, McGowan later provided the worst when a long, loose pass to ground was hacked on by Xavier Garbojosa to make it 27-13.

Even then, with Leinster's fitness levels more than passing their biggest test so far, they converted intense pressure to sandwich Toulouse's fourth try with two of their own in the last 12 minutes.

But after the first, Aaron Freeman missed the restart and the ball deflected off Steve Jameson to Didier Lacroix, and the pressure ultimately resulted in a well-taken try by the quick centre Pierre Bondouy. And after the second, when Declan O'Brien burrowed over, McGowan's conversion hit the upright to leave him with four kicks out of nine and Leinster tantalisingly out of reach.

Comparing that with Stephane Ougier, who missed only his last and unimportant seventh kick, it's clear that Leinster might well have got something more tangible out of this game.

While "terribly disappointed to lose the game; we don't enjoy losing", Mike Ruddock was understandably phlegmatic. "We only had five of the side that played against Pau, this is a new team," he pointed out.

Ruddock and Glennon extracted particular encouragement from the performances of newcomers this season, such as Trevor Brennan, Reggie Corrigan and late arrival Declan O'Brien, and stressed that all were playing second division club rugby last season.

Brennan, heretofore confined to one pre-season game last year before this campaign, has been Leinster's best player over the last month. He is an awesome hitter. Having put Deylaud out of the game, legitimately, he decked Ougier and four Frenchmen gathered around him. He got under their skin.

After the first French try, he turned to his forwards on the halfway line and urged "C'mon lads, no respect," and was promptly first up to win the restart. The next Leinster scrum screwed awkwardly, but Brennan punched over the gain-line and passed to Victor Costello (who had another good game). Brennan was everywhere.

Immensely strong and often nakedly aggressive, he walked a thin line and was yellow-carded for a second aerial assault at a restart - though the penalty was more costly and was nothing compared to Hugues Miorin's studded assault which the officials chickened out of. "Number seeex, hee sucks," roared the pocket of Toulouse supporters, and who later booed Brennan's man of the match award - the ultimate seal of approval.

With his bitten eyebrow - no kidding - patched up, Brennan returned to the fray with undiluted gusto. His performance was compulsive viewing, a bit like watching Roy Keane in full flight.

The last try was in many ways down to him, as he took O'Mahony's tapped penalty and bounced three Toulouse forwards off him before off-loading - an area of his game that has improved immeasurably.

Scoring sequence: 3 mins: McGowan penalty 3-0; 14: McGowan penalty 6-0; 27: Marfaing try, Ougier conversion 6-7; 37: Begue try, Ougier conversion 6-14; 41: McGowan try, McGowan conversion 13-14; 46: Ougier penalty 13-17; 53: Ougier penalty 13-20; 65: Garbojosa try, Ougier conversion 13-27; 69: penalty try, McGowan conversion 20-27; 72: Bondouy try, Ougier conversion 20-34; 77: O'Brien try 25-37.

Leinster: K Nowlan (St Mary's College); D Hickie (St Mary's College), M Ridge (Old Belvedere), K McQuilkin (Lansdowne) capt, J McWeeney (St Mary's College); A McGowan (Blackrock College), D O'Mahony (Lansdowne); R Corrigan (Greystones), S Byrne (Blackrock College), A McKeen (Lansdowne), S Jameson (St Mary's College), A Freeman (Lansdowne), T Brennan (St Mary's College), T Goldfinch (Blackrock College), V Costello (St Mary's College). Replacements: P Bruce (Terenure College) for McKeen (66 mins), D O'Sullivan (Skerries) for Goldfinch (73 mins), D O'Brien (DLSP) for Jameson (73 mins). Temporary replace- ments: O'Brien for Brennan (42-47 mins), C Clarke (Terenure College) for McWeeney (4751 mins).

Toulouse: S Ougier; M Marfaing, R Paillat, P Bondouy, X Garbojosa; C Deylaud, J Casalbou; C Califano, J Begue, F Tournaire, H Miorin, F Belot, D Lacroix, F Pelous, S Dispagne. Replacements: N Martin for Deylaud (10 mins), C Labit for Pelous (47 mins), D Couzinet for Dispagne (73 mins), D Berty for Garbojosa (73 mins).

Referee: C White (England).