A try in the last move of the game, five minutes into injury time, gave Ballymena their wafer-thin 28-27 victory over Dungannon in the Senior League.
Both teams have now lost twice and with nearly half the fixtures completed it has made the undefeated City of Derry firmer favourites for the title although Ballynahinch, Malone and Belfast Harlequins have only been defeated once.
It was an exciting game at Stevenson Park where the home team built up an eight point advantage but conceded three tries in the second quarter to help Ballymena to a 21-13 interval lead.
Again Dungannon proved their resolve to be 27-21 ahead after 65 minutes and when it looked as though they would hold on for victory, Ballymena's Scott Gibson was in support to touch down and then add the key conversion.
The scrum half also converted the other tries by David Whann (2) and Adie Hamilton. For Dungannon David Egner (2), Mark Faloon and Tim Smith scored with Stuart McCloskey converting two and Jarryd Bennett adding a penalty.
City of Derry can start their AIL campaign against UCC on Saturday with confidence following another win, this time against Queen's 38-25.
Derry were also awarded a penalty try, the other scores coming from Stephen Corr (2), Andy Bratton and Josh Lewis while Richard McCarter had two conversions.
Stuart McIlwaine, John Russell and Peter Storey were the students' try scorers.
Elsewhere, Malone saw off Rainey 41-23.
The undefeated U20s were too strong for Munster 18-9 at Musgrave Park where out half Stuart Olding controlled the contest.
Olding kicked two penalties and converted one of the tries from John Donnan and replacement Mark Best.