With Blackrock clearly below their best at Stradbrook on Saturday, Clontarf - urged towards frantic measures by their proximity to the bottom of the table - raised their tempo and sensed early on that the home side did not have an appetite for their controlled passion and commitment.

The front five dominated the tight and with Craig Brownlie, Pat Ward and Dave Moore prospering in the loose, Clontarf led from seven minutes into the game to haul themselves up three notches on the table in what now has become an ever changing first division.

Blackrock will look at the injury to out-half Alan McGowan as pivotal and it was - but not to the extent of a 13-point margin. When McGowan hobbled off with a knee injury after one minute, it was hardly likely that their under-20 Neil O'Donovan could be ushered in to fill such an important role.

Blackrock might take cold comfort from the fact that their brand of rugby, while lacking any cutting edge, largely entertained. Nicky Assaf buzzed as usual and Brian Carey in the centre accepted a creative role and frequently flourished. His diagonal chip on the run to the corner for Aidan Guinan's second-half try oozed composure.

Clontarf's strength was their ability to stonewall when necessary and capitalise when the opportunity arose even with the loss of scrum-half Ronan O'Reilly after 26 minutes.

Out-half Richie Murphy typified Clontarf's competence. Two 40 metre kicks sent his side 6-0 ahead before Ollie Winchester rifled down the wing for his try, Murphy converting for a 13-0 advantage. Although Carey brought it back to 3-13 with Blackrock bringing the first half to a close with a flourish, it was short lived. Murphy added three more points before number eight Dave Moore picked up on the open side of a scrum to squirm through the stretched Blackrock cover for a one-handed slam-dunk try. Murphy converted on the 53rd minute and the match at 3-23 was over as a contest.

Guinan and Carey clawed back some ground with tries but it was a demonstration of superb handling by the entire Clontarf line ending with Craig Brownlie's corner try that livened up the bitter afternoon.

Scoring sequence: 7 mins: Murphy penalty, 0-3; 19 mins: Murphy penalty, 0-6; 31 mins: Winchester try, Murphy conversion, 0-13; 35 mins: Carey penalty, 3-13; 46 mins: Murphy penalty, 3-16; 53 mins: Moore try, Murphy conversion, 3-23; 57 mins: Guinan try, Carey conversion, 10-23; 61 mins: Brownlie try, 10-28; 82 mins: Carey try, 15-28.

Blackrock: T Keating; A Guinan, B Carey, M Roche, D Quinlan; A McGowan, N Assaf; P Flavin, S Byrne (capt), P Jordan, R Casey, H Kos, R Wheeler, D Kennedy, L Cullen. Replacements: N O'Donovan for McGowan (7 mins), T Stapleton for Kennedy (71 mins).

Clontarf: M Woods; D McElligott, M Smith, S Fitzsimmons, O Winchester; R Murphy, R O'Reilly; H Hurley, B Jackman (capt), P McQuillen, R Foster, C Power, C Brownlie, P Ward, D Moore. Replacements: S Bertis for O'Reilly (26 mins).

Referee: B Campsell (Manchester).