TULSA, Okla. -- Jessica Shults' two-run single in the sixth inning broke a 1-1 tie and propelled No. 1 Oklahoma (31-2) to a 3-1 win at No. 18 Tulsa (29-8-1) in a midweek pitchers' duel.

The win gives Oklahoma its nation's-leading 11th victory against a top-25 team. In addition, the team's .846 winning percentage in such games is also the best in the country for teams that have played more than one top-25 foe.

Runs figured to be at a premium on Thursday as Oklahoma starter Michelle Gascoigne entered the matchup with the nation's top earned run average at 0.62. Her counterpart, Tulsa's Aimee Creger, was third at 0.86.

It was Oklahoma, though, that was able to solve the opposing pitcher. Creger allowed all three runs, marking just the third time in 20 appearances this season in which she gave up more than one run.

Both pitchers went unscathed through the first two innings as neither allowed a hit. But the Sooners finally broke through and got on the board in the third inning.

Senior Brianna Turang picked up the first hit of the game when she singled with one out to left field. After a wild pitch moved her to second, sophomore Lauren Chamberlain recorded a single of her own to put runners on the corners.

Following a steal of second by Chamberlain, sophomore Georgia Casey laid down a squeeze bunt. The small ball tactic enabled Turang to hustle home from third and beat the throw to the plate.

Tulsa tied the game up at one when Samantha Cobb hit a solo home run to lead off the bottom of the fourth. It was the first hit or baserunner for the Golden Hurricane after Gascoigne retired the first nine batters of the game.

The Golden Hurricane threatened to move in front in the bottom of the fifth when they put runners on first with one out, but Keilani Ricketts came on in relief and get two strikeouts to end the frame.

Gascoigne ended the game with six strikeouts and three hits allowed, including the solo shot by Cobb, during 4.1 innings of work. She has now given up one earned run or fewer in 17 of her 19 appearances this season and hasn't allowed two earned runs in a game since Feb. 22.

Having thwarted the home team's scoring chance, Oklahoma took the lead in the sixth.

Casey led off the frame and was hit by a pitch. Fellow sophomore Shelby Pendley then laced a double to the gap in left center to put two in scoring position with no one out. Senior Jessica Shults followed with a single to shallow left center to plate the pair and put OU on top 3-1.

Ricketts got the win to improve to 16-1, but Tulsa wouldn't go down without a fight.

Lacey Middlebrooks led off the seventh with a single to right field. Julie Kernen was then hit by a pitch to bring the winning run to the plate. Ricketts battled back to strike out pinch hitter Amy Harrison and induce a weak comebacker from Cassidy Bowen, but the Golden Hurricane loaded the bases when Catherine Horner was hit by another pitch.

With the winning run now on first base, Jodi Edmiston slapped a 1-1 pitch, but ended up making contact with the ball after exiting the box, resulting in the game's final out.

In securing the win, Ricketts struck out five and gave up just one hit during the game's final 2.2 innings.

Creger ended up with the loss for Tulsa, dropping her record to 15-3. She gave up six hits and three earned runs in six innings and struck out five while walking one.