Under-21 World Cup semi-final/Ireland v Australia: They'll start the match as clear underdogs, a mantle that sits easily with Irish teams historically. This game, though, is about the size of the fight in the dog not the size of the dog in the fight.

Ireland cannot demonstrate a scintilla of satisfaction for what they have achieved already in this tournament and that will be tough, for two of their three wins in the pool stages were outstanding results. When they take to the pitch at Hughenden in Glasgow tonight the only thing that matters is 80 minutes plus against the Australians.

There has to be that single-mindedness, that mental hard edge that will not accept the pat on the head for reaching the semi-finals and be satisfied by the plucky-Irish tag. This is an opportunity for a young Irish team to lay down a marker on the rugby pitch that could have ramifications right up to the 2007 World Cup and beyond.

Australia won't underestimate Ireland but not for one minute will they consider that they could lose this match. True to their professional nature, they will have analysed Ireland to the nth degree, poring over match videos and identifying weak areas.

Ireland will have to earn the right to win and play at a level they haven't broached in the tournament to date. That's not to say that Mark McDermott's side aren't capable of stepping up to the plate.

The pack, in which Trinity number eight Jamie Heaslip has been outstanding, have proved more than a match for most opponents and that includes Argentina. In that collision it was the Pumitas that blinked first.

The weather forecast for Glasgow is for a cool evening dominated by heavy showers, conditions that illustrate the importance of the forward battle. Captain David Gannon leads by example and will be looking to draw big-game players Denis Fogarty, Shane O'Connor and Heaslip into the match.

David O'Brien had a superb game against France and he'll have to be even more durable tonight. The Aussies like to play at pace, blowing away tacklers at ruck time and looking to maintain a high tempo with an emphasis on passing out of the tackle.

O'Brien, and the excellent Brendan O'Connor, have to insinuate themselves into rucks and slow down ball, frustrating the Australia game-plan.

Tomás O'Leary was another to produce a quality display against France. The Aussies will have noted his tendancy to seek gaps on the fringes and herein lies the crux: can Ireland make enough subtle changes to the way they play to surprise the Australians.

Outhalf Gareth Steenson is the tournament's leading scorer while centres Glen Telford and John Hearty are perfect foils for one another.

The absence of Tommy Bowe with a shoulder injury - he won't play any further part and has been replaced in the squad by Andrew Trimble - is a blow and that's not a reflection on his deputy Paul McKenzie. Bowe just has that X factor.

Australia played the same teams as Ireland in their pool matches and built on a narrow win over France to a very impressive 41-3 thumping of Argentina.

The comparison suggests an Australian victory. History supports that assertion, as does the fact that this game represents the fourth in 12 days for this Irish team. They haven't had the luxury of making many changes to the starting XV unlike the Australians.

If, however, Ireland turn up to Hughenden with something more substantial than hope in the hearts, play to the limit of their ability and enjoy a little luck then the pats doled out could be on backs and not on heads.

IRELAND: A Finn (Dolphin); R Lane (UCC), J Hearty (Blackrock), G Telford (Dungannon), P McKenzie (Loughborough University); G Steenson (QUB), T O' Leary (Cork Constitution); J Wickham (Clontarf), D Fogarty (Cork Constitution), D Fitzpatrick (Belfast Harlequins); D Gannon (Blackrock, capt), S O'Connor (Cork Constitution); B O'Connor (Cork Constitution), J Heaslip (Dublin University), D O'Brien (Old Belvedere). Replacements: C Geoghegan (UCD), K Doyle (UCD), N McComb (Dundee HSFP), O Hennessy (Dungannon), R Shaw (Wasps), M Glancy (Loughborough University), B O'Donnell (UL Bohemian).

Referee: B Lawrence (New Zealand).

Paths to the semi-final - Ireland: beat Tonga 43-5; beat Argentina 26-22; beat France 27-19. Australia: beat France 25-24; beat Tonga 64-0; beat Argentina 41-3.

Leading points scorers - Ireland: Gareth Steenson 44. Australia: Daniel Halangahu 23 Leading try scorers - Ireland: Tommy Bowe, Richard Lane 2 each. Australia: Lei Tomiki 3.

P W D L F A B ... Ps

New Zealand 3 3 0 0 201 43 3 ... 15

Australia 3 3 0 0 130 27 2 ... 14

Ireland 3 3 0 0 96 46 1 ... 13

South Africa 3 2 0 1 123 90 3 ... 11

England 3 2 0 1 61 70 0 ... 8

Wales 3 1 0 2 86 61 3 ... 7

France 3 1 0 2 70 78 3 ... 7

Argentina 3 1 0 2 68 77 2 ... 6

Italy 3 1 0 2 67 73 2 ... 6

Scotland 3 1 0 2 58 111 1 ... 5

Tonga 3 0 0 3 8 138 0 ... 0

Russia 3 0 0 3 31 185 0 ... 0