FAIRFAX, Va. - A one-out RBI single by Saint Joseph's freshman Sarah Ostaszewski in the bottom of the seventh lifted the third seeded Hawks past sixth seed George Mason, 3-2, in the opening day of the 2017 Atlantic 10 Softball Championship.

With the score tied at 2-2 entering the bottom of the seventh, the Hawks got singles from Molly Kapala and Jancarla Herrera to leadoff the home at-bat. Following a pop out, Ostaszewski drilled a single off the right field wall, scoring Kapala to give SJU the victory.

Saint Joseph's now advances to face second seed Massachusetts in the quarterfinals of the winner's bracket on Thursday at 12:30 p.m.

The sixth seed George Mason took the lead from the start as the Patriots opened a 2-0 advantage in the top of the first on a two-run single Erin Calpin.

Saint Joseph's battled back to tie the game at 2-2 in the bottom of the fourth as the Hawks took advantage of a pair of mistakes by George Mason's defense.

The Hawks broke through for their first run in the bottom of the fourth as rookie Caela Abadie scored from third on a wild pitch with the bases loaded. Following a walk to Taryn Grober, Kapala scored senior Kaylyn Zierke from third on a fielding error by the Patriots' second baseman to tie the game at 2-2.

In the circle, SJU junior Madison Clarke relieved starter Ashley Ventura in the fifth and kept the Patriots' bats silent from there as she tossed three scoreless innings and added a strikeout to improve to 8-7 on the year. Ventura finished the game allowing two runs on six hits and added three strikeouts.