Number 8 Michael Noone helped himself to a hat-trick of tries at Anglesea Road as Clontarf maintained their push for the Ulster Bank League Division 1A play-offs and Old Belvedere fell to the bottom of the table.
Garryowen and Terenure College were the only teams to move up the table in round 13 of Ulster Bank League Division 1A, although bonus point wins for leaders Lansdowne and defending champions Clontarf saw them gain slight ground on their top four rivals.
The gap between Division 1B leaders Buccaneers and the chasing pack is now a full 16 points after they overcame UL Bohemians 39-27 in an action-packed eight-try thriller on the University's 4G pitch. Elsewhere, lowly Dolphin and Galwegians gave themselves a boost with hard-fought wins.
Division 1A's top four clubs, along with Garryowen who have climbed into fifth place, all won on a busy day in the Ulster Bank League, while relegation-threatened pair Dolphin and Galwegians bounced back with morale-boosting victories in Division 1B.
Division 1A's top two clubs and the bottom two are all hoping to make the most of home advantage on Saturday. Having found their groove again with three wins on the trot, bottom side Terenure's clash with third-placed Cork Constitution could be the match of the day.
There are two crunch clashes at opposite ends of the Division 1B table on Saturday afternoon, as leaders Buccaneers visit their closest challengers UL Bohemians and bottom side Dolphin look to halt Shannon's recent resurgence.
There are two eye-catching matches at both ends of the Division 2A table on Saturday as Banbridge host fellow promotion chasers Nenagh Ormond and Belfast Harlequins make the trip to Cashel in a crucial basement battle.
Despite the wintry conditions around the country, the teams in Division 1B had little difficulty in finding the try-line on Friday and Saturday with five home wins - four of them by way of a bonus point.
Lansdowne and Buccaneers both extended their leads at the top of Divisions 1A and 1B respectively this weekend, while it remains tight in the other three divisions with Greystones notably nipping ahead of long-time Division 2B leaders Armagh.
Leaders Lansdowne's visit to mid-table UCD is the pick of the Friday Night Lights clashes in Division 1A, while two of the top four sides meet on Saturday as Clontarf host Cork Constitution at Castle Avenue.
With seven rounds remaining, it looks a two-horse race for the Division 2B title and automatic promotion. Armagh and Greystones are nine and eight points clear respectively of a chasing pack headed up by Old Crescent and Wanderers.