Dungannon Swifts 2-1 Donegal Celtic
Dungannon's win over nine-man Donegal Celtic means they will definitely stay in the Premiership if they avoid defeat away to Glenavon next Saturday.
The Swifts scored in the third minute when Stefan Lavery's cross was turned in by Thomas Lambe for an own goal.
It was 2-0 in the 15th minute when Ryan Harpur's shot took a deflection to beat keeper Robert Robinson.
Darren Murray scored a penalty for DC who had Stephen McAlorum and Lambe sent-off in the second half.
McAlorum, moving to Glentoran next season, was dismissed in the 75th minute for a tackle on Harpur.
It means a suspension will deprive the DC skipper of the chance to make a farewell appearance at the Suffolk Road in the last match of the season against relegated Carrick Rangers.
Lambe got a second yellow card in stoppage-time for kicking the ball away.
Murray's 73rd-minute spot-kick came after Sean Kyle had upended Michael Funston.