Spencer Grogan scattered six hits over seven innings of work to improve to 3-3 on the year. He gave up just one unearned run while walking three and striking out four.
The Cowboys improved to 20-9 and 6-2 in Big 12 play, while Kansas State dropped to 10-18 and 0-8 in conference play.
OSU scored three runs in their first opportunity. Josh Fields drove in the first run with a single that fell in front of right fielder Gabe Luttrell. John Urick hit a ground ball to first to score Jose Virgil and Mario Matulich scored Fields on a base hit between the first and second basemen.
Brandon Taylor reached on an error by Chris Gutierrez and later scored to put Kansas State on the board in the third inning.
The Cowboys scored four unearned runs in the bottom of the fourth to stretch the lead to 7-1. Josh Fields reached on an error by third baseman Ty Soto that should have been the third out of the inning, but instead it allowed Gutierrez to score from third. John Urick followed with a three-run homerun off the screen in left field to make it 7-1.
OSU scored three more runs in the fifth and added another in the seventh to close out the scoring in the game.
Gutierrez, centerfielder Jose Virgil and Fields led the Cowboys offensively with three hits each, while designated hitter Mario Matulich aided the cause with two hits.
The two teams will be back in action tomorrow at 2 p.m. in the series finale.