Pegasus missed the chance to tighten their grip on an All Ireland League play-off place after they lost 1-0 to Railway Union in Belfast on Saturday.
The win takes Railway Union above Pegasus and into second place.
Ulster Elks are up to third after a 3-1 win at Greenfields while Ards drew 1-1 at Cork Harlequins to remain two points above the relegation play-off.
In the men's league Lisnagarvey made it 11 straight wins with a 3-2 home success over Cork C of I.
With Hermes already crowned champions there are two places up for grabs in the end of season play-off finals and the race tightened up after Saturday's results.
Sinead Dooley grabbed the winning goal for Railway Union at Queen's with under two minutes remaining as she raced clear of the Pegasus defence before keeping her composure to score.
The Dublin side are a point ahead of three teams separated only on goal difference.
Megan Frazer drag flick from a penalty corner gave Ulster Elks an early lead and two goals from Rebecca Barry secured the points. Pegasus drop to fourth ahead of UCD who where held by UCC in a 2-2 draw.
On Sunday the Elks host Railway Union while Pegasus travel to UCD.
In the battle to avoid the relegation play-off an equaliser from Amy Benson gave Ards a draw at Cork Harlequins and they remain two points clear of UCC ahead of their clash in Cork on Sunday.
Champions Hermes were beaten 2-1 by Pembroke.
Lisnagarvey continue on their way towards the men's title but they were made to work hard for their win over Cork C of I.
John Jermyn put the visitors in front from a penalty corner before Sean Murray equalised for the home side and Timmy Cockram's third quarter goal appeared to have put Garvey on the road to victory.
But back came Cork through a Philip Sweetnam strike only for Matty Nelson to score the winner with only five minutes to go.
Garvey increased their lead to 11 points over Monkstown, who were held 1-1 at home by fourth-placed Three Rock Rovers while Banbridge remain third after a 2-2 draw at Pembroke Wanderers.
At the bottom goals from James Cox and Matthew Crookshanks helped Annadale to a 2-0 home win over Glenanne, lifting them off the bottom of the table on goal difference as Cookstown replaced them following a 6-3 thumping at Railway Union with Mark English scoring a hat-trick.
The two Ulster sides remain two points behind Cork.