After going up by a run in the top of the 13th inning, Oklahoma State gave up two runs in the bottom of the frame and suffered a 5-4 loss to 18th-ranked Baylor Sunday at Baylor Ballpark.
The Bears collected four hits in the decisive inning, with Josh Turley's pinch-hit single bringing home the game-winning run to give BU the series sweep.
With the loss, the Cowboys fell to 1-5 in Big 12 Conference play and 14-14 overall. The win was the 11th straight for Baylor as the Bears stayed perfect in league play at 9-0 and are now 22-7 overall.
OSU outhit the Bears by a 15-11 margin, but the Cowboys left 13 runners on base.
Blake Barnes suffered the loss on the mound to fall to 1-3 on the year. The senior right-hander worked the final five innings, allowing two runs on seven hits and striking out five.
Trey Whaley and Robbie Rea combined for seven hits to lead the Cowboy offense, with Whaley's four hits tying a career high, while Gabe Weidenaar drove in a pair of runs.
After the game had been tied at 3-3 for five-straight innings, OSU rallied in the 13th. Whaley led off the frame with an opposite-field double and then advanced to third on a wild pitch. Saulyer Saxon then came up big with a pinch-hit single past a drawn in Baylor infield to put the Cowboys on top, 4-3.
Later in the inning, OSU would have runners on first and second with one out, but the Cowboys failed to add more runs.
In the bottom of the inning, Nathan Orf led off with a single for the Bears, and Max Muncy followed with a double to put runners on second and third. BU collected its third-straight hit on an infield single by Josh Ludy that brought home the tying run.
Following an intentional walk to load the bases, Turley stepped to the plate and delivered a single up the middle to bring home the winning run.
OSU scored the first three runs in the contest. The Cowboys took a 2-0 lead in the fourth on an RBI groundout by Mark Ginther and a sacrifice fly by Weidenaar, then added their third run in the sixth on Weidenaar's RBI single.
Spotted a 3-0 lead, OSU sophomore Vince Wheeland, making the first Big 12 start of his career, dominated the Bears through the first six innings, holding them hitless and striking out five.
However, after recording the first out in the seventh, Wheeland surrendered back-to-back singles, then lost the shutout when Cal Towey delivered a three-run home run that tied the score and ended the Cowboy righty's day on the mound.
The Cowboys return to action Tuesday when they host Wichita State at 6:30 p.m. at Allie P. Reynolds Stadium.