OKLAHOMA CITY — Ella Parker hit a three-run, walk-off homer with two outs in the bottom of the seventh inning to lift Oklahoma to a 4-3 victory against Tennessee in the Women’s College World Series opener for both teams on Thursday.

Parker’s second homer of the game off Tennessee’s Karlyn Pickens strengthened the Sooners’ chances of winning a fifth straight national title.

Pickens, a National Fastpitch Coaches Association first-team All-American, had dominated most of the game, with her pitches regularly hitting 75 mph, before faltering late.

Ailana Agbayani opened Oklahoma’s half of the seventh with a walk. Pickens retired the next two hitters before Oklahoma’s pair of first-team All-Americans came through. Kasidi Pickering singled and moved Agbayani to third before Parker’s blast to center ended the game.

Second-seeded Oklahoma (51-7) advanced to face No. 6 seed Texas, a 3-0 winner over No. 3 Florida in its opener, on Saturday for a spot in the semifinals.

Oklahoma has beaten Texas in the championship series in two of the past three years, and both programs jumped from the Big 12 to the Southeastern Conference this season.

No. 7 seed Tennessee (45-16) will face Florida in an elimination game Friday.

Oklahoma pitcher Sam Landry, a second-team All-American, hung tough and got the win, despite trailing nearly the entire game. She scattered eight hits and allowed just one earned run.

Tennessee jumped on Landry with two runs in the first. Parker hit a solo shot off Pickens to trim Tennessee’s lead to 2-1. The Volunteers added a run in the third when Ella Dodge scored on a dropped fly ball.

Tennessee loaded the bases with one out in the seventh, but Oklahoma turned a double play and the Volunteers did not score.