PROP forward Rob Sweeney scored two tries in a manof-the-match performance as Clontarf kept their league ambitions intact with an impressive second-half performance at Stradbrook.

The northside club ran in five tries, four of them in the second half, to pick up a vital bonus point and consign Blackrock to their second successive heavy defeat in the All Ireland League.

Phil Werahiko's men were clearly the better side throughout and having failed to convert their dominance into a clear-cut half-time lead, they turned on the power after the break with Sweeney (twice), Niall O'Brien and Breiffne O'Donnell all touching down.

While they trailed just 3-5 at the break, Blackrock had a chance to sneak in front in the 50th minute but Paddy O'Toole snatched at his longrange penalty attempt and failed to get the ball airborne.

That served as a warning to Clontarf and their reply was as devastating as it was swift with O'Brien, Sweeney and O'Donnell touching down three times in the space of 10 minutes to put the game beyond a committed but toothless Blackrock outfit.

Sweeney grabbed his second score of the game in the fourth minute of added time . . . the referee played an extra 10 minutes . . . in what was an outstanding performance of power and commitment.

However, the score that turned the game Clontarf 's way was scored by O'Brien on 53 minutes after the ball had passed through five pairs of hands before the powerful winger cut a swathe through the centre to score near the posts.

Conor O'Shea added the conversion to make it 12-3 for the visitors before Sweeney and O'Donnell ploughed their way through Blackrock's right flank to increase that lead to 21 points by the 63rd minute.

Rock had started the new year in the worst possible fashion when they were crushed 49-0 by Cork Con last weekend.

And they can have no complaints about the manner of their defeat on home territory yesterday against a Clontarf side that will have plenty more to say in the battle for the title.

Despite playing into the sun in the first half, Clontarf started in blazing fashion with left wing Derek Keane tackled into touch at the corner flag after just six minutes.

Blackrock had spurned a first-minute penalty chance through out-half O'Toole but were soon trailing as the impressive Keane touched down on the overlap on 13 minutes after handing off the challenge of Rock's Karl Gilligan.

Daragh O'Shea's touchline conversion attempt ricocheted wide off an upright to leave the visitors just five points in front and it seemed inevitable at that stage that the points would head north of the Liffey.

Clontarf were especially strong in the loose with Jacob Ellison and Magnus Coetzer a constant threat at wing forward and while Rock threatened briefly midway through the opening half, they never had enough firepower to get points on the board.

O'Toole missed a longrange penalty chance on 18 minutes and eventually opened Rock's account on 24 minutes with a skudding drop goal.

But his side's struggles became patently evident from the 28th minute when Coetzer was shown a yellow card by referee Ken HenleyWillis as Clontarf threatened to score again.

Despite being reduced to 14 men, it was the visitors who looked more likely to score in what remained of the second half and had it not been for an untimely knock-on, a bludgeoning leftflank attack by Keane and lan Trenier would have yielded a second Clontarf try.

BLACKROCK COLLEGE F Carr; K Gilligan, G Brown, P Graham, A Henry; P O'Toole, P Beirne; C Murphy, D Gavin, M Cuffe, V Ryan, O Cullen, D Dillon, D Laffin, E Manawaiti Subs G Fitzgerald for Cuffe, 47 mins; S Madigan for Ryan, 58 mins, K Copeland for Gilligan, 63 mins

CLONTARF D O'Shea; N O'Brien, M Hewitt, B O'Donnell, D Keane; P O'Brien, F O'Loughlin; K Dorrian, N Carson, R Sweeney, A Trenier, B Gissing, J Ellison, M Coetzer, P Purdue Subs D O'Brien for Coetzer, 51 mins; P Whately for Carson, S Brophy for Dorrian, both 75 mins Referee K Henley-Willis (IRFU)