Lauren Chamberlain's two-run home run in the bottom half of the 12th inning helped the top-ranked Oklahoma Sooners capture a 5-3 come-from-behind victory over the seventh-ranked Tennessee Lady Vols in the first game of the best-of-three Championship Series of the 2013 Women's College World Series, in Oklahoma City, Oklahoma, on Monday night.

After ten scoreless innings, each team scored three runs in the 11th before Chamberlain's blast capped the longest postseason game in WCWS championship game or championship series game since 1984, when UCLA beat Texas  A&M, 1-0, in 13 innings to win the title.

Tennessee grabbed the lead in the top half of the 11th inning, when Jordan Shipman slugged a three-run home run, breaking the scoreless tie, and giving the Lady Vols a 3-0 lead.

That's when Oklahoma rallied.

With one out in the frame, Keilani Ricketts doubled on wind-aided popup off the glove of Lauren Gibson, before Brittany Williams doubled, driving home Ricketts, to cut the Tennessee lead to 3-1.

With two outs, Destinee Martinez tripled, scoring Erica Sampson, who was running for Williams, to trim the Lady Vols lead to 3-2, before Callie Parsons doubled, scoring Martinez, and evening the game at 3-3.

In the bottom half of the 12th inning, Oklahoma's Brianna Turang doubled down the left field line, bringing up Chamberlian, who crushed the first pitch of the at-bat just inside the left-field foul pole, giving the Sooners the dramatic win.

For Chamberlian, it was her 30th home run of the season and 60th of her career.

With the win, Oklahoma improved to 56-4 on the year, while Tennessee fell to 52-11.

Game two of the best-of-three game series is scheduled for Tuesday night, at 7 o'clock.

If Oklahoma wins, they would capture their second national title, and first since 2000.

If Tennessee wins, it would force a third and decisive game, on Wednesday night.