The proverbial game of two halves for manager Mick Byrne and his Shamrock Rovers side. In the first they were disappointing, in the second dismantled.

The one-time Cup specialists' manager hardly needed reminding afterwards that their once-promising season is reduced to a scramble for third place in the league and, most probably, a place in the Inter-Toto Cup.

Even that will be beyond them, however, if they produce many more performances like yesterday's, while Shelbourne's sudden rediscovery of their own best form would suggest that it is they, rather than Rovers, who can impress in both league and Cup.

Dermot Keely's side had the better of what was an open and entertaining tie yesterday. Their greater effectiveness up front was the sole factor which produced their one-goal lead at half-time, but their superiority over the course of the second period was hardly reflected at all in the two goals Pat Scully added.

The Rovers players, under no illusions regarding what a defeat would mean to their season, simply crumbled in the face of a more determined and purposeful side and if they didn't realise that they had let themselves down then it could hardly have escaped them by the time Byrne had finished his 45-minute post-match dressingroom dressing down.

"We weren't professional enough to do the job," said the clearly-despairing manager when he emerged to face the media. "We didn't want it enough, we didn't work hard enough and if you don't work hard in this game you get nothing, which is precisely what we deserved to get out there this afternoon."

Sheepishly, some of his players filed out past him in the background, but they must have known it was the truth. For 45 minutes they had competed well, particularly in midfield, without ever threatening to take control of the tie, but when things got tough their heads went down. Through much of the second half it seemed inconceivable that they would get away with even a respectable-looking scoreline.

At the back they constantly looked uneasy, while up front the fact that Tony Cousins as well as first Jason Sherlock and then Brendan Markey were having to come deep and receive the ball with their backs to goal, meaning that the threat they posed was almost negligible.

At the other end Tony Sheridan was his usual bag of tricks but, perhaps more importantly, Stephen Geoghegan looked as sharp as he has ever done this season, a fact underlined by the speed with which he pounced to drive home a loose ball after Eoin Heery's shot had been deflected off his striking partner.

The goal had started with a defensive error by Tommy Dunne. The former Derry player initially appearing to have done well to prevent a throw in and then a corner but having done the hard stuff the Rovers full back, under virtually no pressure, knocked the ball straight to Sheridan.

Scully's two second-half efforts also owed much to the shortcomings of the home side's back four. The first, after 56 minutes, was a sweetly-struck volley, but by the time it arrived on the big defender's doorstep from Dessie Baker's corner there had been countless opportunities to clear the danger. The second, a minute later, involved a free kick from Baker, and this time there was none of the mucking around before the ball reached Scully, but not much by way of marking either.

At 1-0 down Rovers had themselves gone close - Marc Kenny's long free kick was turned against the post by Paul Whelan from a couple of yards out. In the final minute, too, Billy Woods struck the woodwork. Both managers felt that if the Kenny's effort had gone in there was a chance that it might all have been different, but by the time of Woods's shot even a consolation goal would have flattered them.

Indeed Dunne had almost inadvertently brought Shelbourne's tally to four with a quarter of an hour remaining. Brendan Markey started the move with an abysmal back pass that Dessie Baker intercepted close to half way. He fed Stephen Geoghegan down the right and his low cross for Sheridan was met instead by Dunne who thundered the ball just over his own bar from eight yards out.

Had it gone in it would surely have been one of the great own goals - but then this could describe the whole team's performance anyway.

Shamrock Rovers: O'Dowd; Britton, Palmer, Whelan, Dunne; Kenny, Colwell, Purdy, Tracey; Cousins, Sherlock. Subs: Markey for Sherlock (half-time); Morrisroe for Kenny (59 mins); Woods for Tracey (73 mins).

Shelbourne: Gough; Heery, Scully, McCarthy, D Geoghegan; D Baker, Fenlon, Doolin, R Baker; S Geoghegan, Sheridan.

Referee: J McDermott (Dublin).