KEVIN Croke scored twice as UCD ended Ballynahinch's unbeaten run in Division 2 in a 38-31 classic at Belfield.
Results went both sides' way elsewhere, meaning it's a seven-point gap to Belfast Harlequins in third after they beat Bective 18-17.
Midleton are up to fourth after a 12-11 win over Terenure, while Malone stunned Ballymena 20-15.
Queens hammered basement boys Thomond 50-15, while Old Crescent climbed out of the relegation zone by beating Corinthians 14-9, as Clonakilty slipped to a 59-27 defeat at Trinity.
In Division 3, Instonians remain in control after a 19-5 win over Navan that left them four points clear at the top.
Seapoint's 28-23 victory over Highfield saw them go second above City of Derry, who slumped to a 22-17 defeat at Rainey. Greystones remained in touch with a 47-11 away win at Nenagh.
Banbridge dismissed Ards 38-3, Sunday's Well went down 14-13 to Barnhall and Suttonians beat Naas 18-13. Connemara look doomed after losing their 10th match, going down 43-23 at Wanderers.