It hasn't taken long for the demarcation lines to be drawn in this season's Guinness Inteprovincials. If tomorrow's table-topper between Ulster and Munster is a summit meeting of the soaraway pacesetters, tonight's Leinster-Connacht duel at Donnybrook is more of the canine variety - ie, dog eat dog.

Were there two divisions instead of two tiers at this juncture, you'd be inclined to label it a relegation eight-pointer. With a view to mounting a campaign for one of the two automatic European Cup spots for next season, it's something of an eight-pointer anyway, for there is surely no way back for tonight's losers.

This isn't anything terribly new for Connacht, even if compared to the last couple of seasons this one has been pretty terrible so far. However, it is new for Leinster and that in turn arguably puts more pressure on them this evening.

Interprovincial rugby at Donnybrook has been a big hit with the Dublin rugby public this past year (if the match fails, the postmatch revelry usually makes up for it) but you'd wonder how long the rugby public's loyalty will be maintained if Leinster keep on losing. Leinster have lost six of their last seven matches at the venue, and since their 9-3 win over Begles-Bordeaux almost 11 months ago, they have suffered seven defeats in a row, conceding an average of 36 points per game.

Leinster currently look like a side short on confidence, and were Connacht to rediscover the stickability of last season, it's conceivable that Leinster might again panic a little as they did against Ulster.

Alternatively, were Leinster to get a couple of quick scores, then their confidence is liable to return and there's plenty of talent through their ranks - especially amongst the backs - to make the most of it.

This evening marks the first occasion the Shane Horgan-Brian O'Driscoll dream pairing in midfield gets a run. Horgan, who is due to play at inside centre, is Leinster's one injury doubt and he has to undergo a fitness test on his turned ankle this morning.

Whereas Connacht have only two members in Ireland's World Cup squad, Leinster have seven. However, Leinster do have seven of the line-up from the corresponding fixture last year, including half the pack that bullied Connacht for an hour last year before the visitors rallied in the final quarter to reduce a 19-0 deficit to a 29-24 defeat, and in the process picked up a couple of bonus points.

Alas, Connacht seem ill-equipped tonight for a similar comeback. Although they will have been buoyed by the return of Gavin Webster and Martyn Steffert from injury, and by their improved showing against Ireland, that latter display still saw them cave-in and concede 28 points in 16 minutes during the second-half.

The Irish match also brought back memories of how Connacht conceded 28 points in 25 minutes against Ulster and 35 points in 19 minutes against Munster. Hence, a couple of quick scores against them tonight and their heads could drop.

Ulster have made two changes for tomorrow's top-of-the-table meeting with Munster at Queen's in Belfast. Andy Matchett, the scrum-half who played in the European Cup final, starts in the absence of Stephen Bell, while former English under-21 winger Spencer Bromley makes his first appearance of the campaign in place of Tyrone Howe, a try-scorer in Ulster's win over Leinster.

Coach Harry Williams admitted that "considerable thought was given to the composition of the second row and back row, where the competition for places is intense," but he relented and stuck to the same pack which played, although under-performed slightly, against Leinster.

ULSTER: S Mason; J Topping, J Cunningham, J Bell, S Bromley; D Humphreys (capt), A Matchett; J Fitzpatrick, A Clarke, G Leslie, P Johns, G Longwell, D O'Cuinneagain, E Miller, A Ward. Replacements: N Malone, R Fredericks, M Edwards, T McWhirter, M Blair, S Best, R Weir.