Stillwater, Okla. ? Kansas University’s bullpen allowed four runs over the final two innings of a 5-3 Big 12 baseball loss to 13th-ranked Oklahoma State on Saturday at Allie P. Reynolds Stadium.

Kansas used a two-run first and a single run in the seventh to take a 3-1 lead into the bottom of the seventh, but OSU scored a single run in the seventh and three more in the eighth.

Kansas junior righty Robert Kahana allowed a run off six hits over 51/3 innings.

“I was pleased that he grinded through the innings,” KU coach Ritch Price said. “He gave us a really solid performance and an opportunity to win when he left with the lead.”

Freshman closer Stephen Villines (1-1) took the loss after allowing three runs — just one earned — off three hits over 11/3 innings.

Villines entered the game with a 0.33 ERA in 272/3 innings pitched, having given up just one earned run in 16 appearances. However, following a throwing error on junior third baseman Aaron Hernandez, which put the tying run on base, OSU second baseman Tim Arakawa homered off Villines in the eighth.

“Obviously, the home run was the biggest play of the game,” Price said. “That was a great swing on that kid’s [Arakawa] part. Villines has been really good for us, but what could have been a great ‘W’ ends up being a devastating loss. But we bounced back after yesterday and competed and played hard today. I can’t ask for any more from my guys than that.”

Kansas fell to 23-18 overall, 6-8 in the Big 12. OSU improved to 28-11, 10-4.

KU will try to avoid the sweep in today’s series finale, slated for 1 p.m. It will be televised live on Fox Sports 1, available locally on WOW! Cable channels 150 and 227.

Kansas 200 000 100 — 3 7 2

Oklahoma State 000 001 13x — 5 10 1

W — Vince Wheeland, 4-0. L — Stephen Villines, 1-1. Sv — Brendan McCurry, 10.

2B — Ryan Pidhaichuk, Kansas; Tanner Crietemeier, Zach Fish, Craig McConaughy, OSU. HR –Tim Arakawa, OSU.

KU highlights — Dakota Smith 2-for-4, R; Aaron Hernandez, 2-for-3; Pidhaichuk 1-for-2, RBI.