Collins the hero for Garryowen
Garryowen and Terenure College were the only teams to climb up the Division 1A ladder, although bonus point wins for leaders Lansdowne and defending champions Clontarf saw them gain slight ground on their top-four rivals.
With Ireland U-20 squad member Peadar Collins crossing in the 62nd minute, Garryowen got back into the top half of the table thanks to a gritty 17-16 victory over UCD at Dooradoyle.
Dublin University endured a seven-try 45-3 drubbing at Lansdowne. Daniel McEvoy scored his 10th try of the campaign and Scott Deasy took his league tally to 142 points as Mike Ruddock's men stretched their lead at the summit to seven points.
No 8 Michael Noone was Clontarf's hat-trick hero in a 36-13 win at Old Belvedere, who are now bottom of the table on scoring difference.
Cork Constitution erased a seven-point half-time deficit as they triumphed 16-10 at Lakelands Park to end Terenure's three-match winning run. Lock Brian Hayes' charge-down try and 11 points from the boot of Tomas Quinlan proved key.
Munster centre Cian Bohane bagged a brace of tries in Young Munster's late 20-18 success against St Mary's. Bohane stung the visitors with a try under the posts in the very last play and teenage out-half Alan Tynan added the decisive conversion.
Buccaneers look destined to claim the Division 1B title after beating closest rivals UL Bohemians 39-27 on the University's 4G pitch. A late intercept try from Connacht's Shane O'Leary settled the issue.
Galwegians won 20-7 at Ballynahinch, with Marc Kelly's closing try ending a three-match losing streak.