It was a night of upsets for some of the clubs chasing promotion from Division Two.
Leaders Gyms were beaten for only the second time this season by second placed Colby.
The southerners won 3-1 at Tromode thanks to two goals from Tom Crawley and a strike from Jamie Heaney.
Gymns are still favourites to go up as Champions but if Colby win their remaining game away to Marown they will guaranteed promotion to the Premier League.
Marown slipped to what could prove to be a costly defeat at home to Malew with Ben Gregson scoring the winner in the 55th minute.
Douglas Royal were held to a 1-1 draw at Ballafletcher by Douglas Athletic - Kevin Ballard put the home side ahead in the first half but Athletic equalised after the break.
In the other match, Onchan won a high-scoring encounter at Braddan 7-5.
In the Premier League, Castletown and Ramsey Youth Centre cling on to top flight status after Michael were beaten 3-1 at Corinthians.