WACO, Texas - No. 25 Oklahoma upset top seed and fifth-ranked Baylor, 4-3, in the semifinals of the Big 12 Championships on Saturday and will challenge No. 9 Texas A&M in the finals on Sunday.

The match came down to the No. 6 spot where OU’s Mihov and the Bears’ Dennis Lengsfeld, ranked No. 92, split the first two sets. Lengsfeld took the first set, 6-3, while Mihov earned a 7-5 win in the second. The third set was decided by a tiebreaker set, which Mihov won, 7-6(5).

Sunday’s finals will be the Sooners first appearance in the Big 12 Championship match after defeating Baylor for the first time since 1997 when OU won 4-3. Oklahoma’s last conference title came in 1992 when it was a member of the Big 8 conference.

“It was a close match,” Oklahoma head coach John Roddick said. “You saw a lot of guys on both sides really leaving it all out there. It was a very similar match to when we played last time. At the end, whoever wins the doubles point turns out to have a huge advantage. We had a mistake to make out there in singles and they didn’t. They made one mistake at six by not holding the serve there. We had that luxury and they didn’t and that was the difference in the match.”

The Sooners jumped out to a 1-0 lead after winning the doubles portion of the match by claiming wins at the No. 2 and 3 spots.

Baylor’s fifth-ranked John Peers and Roberto Maytin struck first in doubles, defeating No. 70 Ionut Beleleu and Tsvetan Mihov at the No. 1 spot, 8-6.

Lawrence Formentera and Laurentiu Gavrila evened the score after the Sooner duo ran away with an 8-4 victory against Kike Grangeiro and Julian Bley at the No. 3 spot.

OU’s Costin Paval and Peerakit Siributwong, ranked No. 73, clinched the match after the tandem won a highly contested battle versus 43rd-ranked Jordan Rux and Sergio Ramirez, 9-7.

In singles action, the Sooners won at the No. 1, 2 and 6 singles spots to earn a spot in the Big 12 Championship against No. 2 seed Texas A&M.

Paval, ranked No. 48 nationally, gave the Sooners a 2-0 lead after the Romanian native quickly disposed of Baylor’s 69th-ranked Ramirez in straight sets at the No. 2 spot.

Rux put Baylor on the board after he downed OU’s Gavrila in identical sets, 6-3.

Maytin tied the score, 2-2, after winning a three-set match at No. 4 singles against Oklahoma's Siributwong. Siributwong took the first set, 6-1, but dropped the next two sets, 6-4, 6-2, to the nation’s 103rd-ranked singles player.

Baylor took the team lead, 3-2, after winning its third consecutive match, this time at the No. 5 spot. There, Formentera took the first set, 7-6(5), but Grangeiro rallied to take the final two sets, 6-2, 6-4.

But OU’s 30th-ranked Beleleu would stop the bleeding, evening the score, 3-3, from the No. 1 spot. Beleleu, took the first set, 7-6(5), but dropped set two, 6-4, to Baylor’s 17th-ranked Peers. The ITA Central Region Champion, Beleleu, proved too strong as he took the third set, 6-3.

Earlier this season, OU dropped a 5-2 decision to the Aggies in Norman, but Roddick is not concerned about exacting revenge.   

“I’m not thinking about winning,” Roddick said. “I’m just thinking about trying to play well and go out and do the things that allow us to go out and compete and be in matches and either take care of matches when we have the lead or at least stay in tough matches and that is all I’m worried about.”