CHARLOTTESVILLE, Va. -- Drew Harrison pitched six innings in his first career start and Jack Mayfield drove in three runs Monday night as Oklahoma beat Appalachian State 5-2 to win the Charlottesville Regional.

Harrison (1-0), a first baseman converted to a pitcher this year, had worked only 9 1/3 innings this season before coach Sunny Galloway handed him the ball for the most important game of the season. He allowed just three hits and two runs, struck out four and walked three.

The Sooners (42-23), who lost their opening game of the regional to the Mountaineers, completed a comeback that saw them eliminate Army and host Virginia on Sunday, then win two against the Appalachian State to advance to the super regional next week at South Carolina.

The Mountaineers (41-18) were making their first NCAA tournament appearance in 26 years and looking for their first regional title, but came up short on a day when the Sooners bats came alive. Oklahoma had 13 hits in winning the opener 14-6, and added 10 more in the clincher.

The Sooners had managed just 11 hits total in their first three games.

Oklahoma also went to work right away after Harrison allowed an RBI double by Daniel Kassouf in the top of the first. Caleb Bushyhead and Evan Mistich walked with one out, and Matt Oberste single in a run, his fifth hit and fifth RBI in as many at-bats to that point on the day.

With two out, Mayfield hit a liner to deep left, and Brandon Burris got a glove on the ball, which then squirted free as two runs scored, giving Harrison a 3-1 lead to work with.

He didn't allow another run until the sixth, and Jordan John came back from pitching eight innings in the loss on Saturday and worked two innings. He left after allowing a single to Jeremy Dowdy start the ninth, and Steven Okert came on and retired the next three to end it.

The Sooners now move to Columbia, S.C., where the Gamecocks are two-time defending national champions and riding an unprecedented 19-game winning streak in the NCAA tournament.

They did it behind Harrison, and by responding every time the Mountaineers scored.

After going ahead 4-1 in the third on Mayfield's sacrifice fly, the Sooner saw Appalachian State pull within 4-2 in the sixth on Daniel Kassouf's sac fly following Callaway's triple.

In the bottom of the inning, the Sooners answered.

Garrett Carey singled with one out, and was erased when shortstop Callaway fielded Erik Ross' grounder up the middle at shortstop and opted to get to the bag himself. He got the out, but Ross beat his throw to first. Ross was then picked off, but the speedy outfielder beat the throw to second, and scored easily on Tanner Toal's single -- hit first hit all weekend.

John worked the next two innings, allowing just one hit until Dowdy singled to start the ninth, and Okert finished it with a strikeout and two fly ball outs.