GLASGOW's gutsy Celtic League challenge ended in Dublin last night as they left it

to the Irish to fight it out. And in exiting the competition, they were given a lesson in the type of rugby they aspire to.

Competitive in every department, utterly impressive in defence and bristling with dangerous runners all round the pitch this Leinster side will return to Lansdowne Road as favourites next week regardless of the outcome when Munster meet Ulster in today's second semi-final.

Yet they were made to work for their win by a Glasgow side which again enjoyed rowdy backing from what would have been unimagined travelling support just a few months ago and while they would almost certainly have won anyway Glasgow errors and a series of good breaks helped Leinster.

A ricochet produced the scrum against the head which led to the games's first score; a Tommy Hayes shot at goal came back off a post, whereas a Nathan Spooner strike went in off the woodwork; Roland Reid was first to the ball as it crossed the line just before the break, but could not get downward pressure, while Shane Horgan scored one of the flukiest tries this ground has witnessed.

Yet Leinster were much the better team as Glasgow under-performed on this second match on the Emerald Isle in less than a week, playing positively without ever looking like living up to the reputation they have developed for scoring freely.

''In the first half in particular we didn't play nearly as well as we wanted to and know we can,'' admitted Richie Dixon, Glasgow's coach. Leinster are a very good side, but that was not all down to them.

''It is about mental toughness at this level and a few of them let themselves down. They are very disappointed, but that is a good thing as long as they learn from the experience.''

Glasgow did make a sprightly start, pinning Leinster inside their half for the opening five minutes without really threatening to break down their hosts, whereas as soon as Leinster got decent possession they made it count immediately as they capitalised on that scrum against the head on halfway.

Victor Costello's run then opened up the defence. The cover postponed the score, but Brian O'Driscoll eventually managed to get the ball to Girvan Dempsey in enough space for the full back to squirm through a tackle and over. From the re-start Glasgow applied pressure but, while they played positively, the difference was that Leinster looked much more dangerous in possession.

Costello was in particularly impressive form and his powerful run from inside his own half to deep into opposition territory opened Glasgow up again and with the cover again stretched O'Driscoll fought his way into the right corner.

Hayes reduced the leeway, but Spooner responded with two well-struck penalties.

In between times Hayes did threaten to change the face of the game with a wonderful break, gliding through a gap in midfield, but was baulked as he pursued his chip.

Nothing was going Glasgow's way and after Andy Henderson was sin-binned just before the break, his killing of the ball also producing the second of those Spooner penalty strikes, two more good chances to get back into the game then went abegging.

First, Hayes saw that well- struck penalty rebound off the right post, then his double miss pass, after Andy Nicol had fielded a weak clearance, was shipped wide on the left to Roland Reid who showed the winger's instincts Scotland want him to develop as he chipped ahead, but could only knock on as he got to the bouncing ball.

Hayes did add a second penalty just after the interval and, with Henderson warming up on the touchline, it looked like Glasgow might just survive their period of being down to 14 men until Leinster produced the flukiest of scores.

Shane Horgan looked to have dropped Brian O'Meara's pass as he attempted to hit the line at pace, however the big centre, who has hardly trained all week because of a virus, showed unexpected dexterity to somehow catch the ball behind his back, barely breaking stride in doing so and the defence hesitated sufficiently to let him power through.

Glasgow could have been forgiven for letting their heads go down at that point, but they responded well with a well worked try as good handling and recycling work was rewarded when Michael Bartlett broke a tackle in midfield to go in close to the posts.

The game was effectively killed off, though, when Horgan made another powerful run in midfield, O'Driscoll appeared on his shoulder to carry it in close, then after the forwards made it available just short of the line, Spooner's inside pass to Denis Hickie put the winger in.

As if to emphasise the fact that this just was not Glasgow's night Spooner's conversion went in off the post and the former Wallaby stand-off added a long range penalty shortly afterwards.

Leinster G Dempsey (P McKenna 64min);

D Hickie, B O'Driscoll (A Magro 77), S Horgan, G D'Arcy; N Spooner (B Willis 74),

B O'Meara; R Corrigan, S Byrne (G Hickie 77), P Wallace (P Coyle 62), L Cullen (B Casey 60), M O'Kelly, E Miller (T Brennan 64), K Gleeson, V Costello

Glasgow R Kerr (B Irving 13-21 & 76); J Steel, J McLaren, A Henderson, M Bartlett; T Hayes, A Nicol (G Beveridge 76); G McIlwham, G Bulloch, L Harrison (E Murray 64), N Ross (S Griffiths 64), J White, G Simpson, G Flockhart, R Reid (A Hall 75)

Referee N Williams (Wales)

Scoring sequence (Leinster first) 7-0,

12-0, 12-3, 15-3, 18-3 (half-time), 18-6,

25-6, 25-13, 32-13, 35-13

Scorers. Leinster. Tries Dempsey (6), O'Driscoll (12), Horgan (46), Hickie (59)

Cons Spooner (6, 46, 59) Pens Spooner

(28, 38, 66) Glasgow. Try Bartlett (52)

Con Hayes (52) Pens Hayes (16, 41)