Glentoran Women defeated Linfield 4-2 on Monday evening at the Blanchflower Stadium, bringing them within five points of Women's Premiership leaders Cliftonville Ladies.
The regular fourteen-game season concluded with the league set to divide into two halves for the remainder of the campaign.
Eva Myles opened the scoring for Linfield after thirteen minutes, but Faye Loughran and Nadene Caldwell restored parity within the opening five minutes of the second half.
Cora Chambers equalised for the Blues in the fifty-fifth minute before Kelly Crompton took the lead for Glentoran.
Naomi McLaughlin sealed the result with a stoppage-time strike to ensure a win for the Glens.
With the split now confirmed, Section A will feature Cliftonville Ladies and Linfield alongside Lisburn Rangers, while Section B comprises Derry City Women, Crusaders Strikers, Lisburn Ladies and Larne Women.
Post-split fixtures are scheduled across Friday 18 September, Friday 25 September and Sunday 4 October.
The focus shifts to the Women's Challenge Cup semi-finals on Friday night, where Lisburn Ladies meet Glentoran and Crusaders face Cliftonville.