Joseph Randle added 80 yards rushing for Oklahoma State, while Mike Gundy improved to 62-32 as the head coach. He's now tied with Pat Jones (62-60-3) for the most wins in school history.
James Sims had 138 yards and a touchdown rushing for the Jayhawks (1-5, 0-3 Big 12), who trailed 20-0 when backup quarterback Michael Cummings took over for Dayne Crist in the third quarter.
Cummings led the Jayhawks to their first touchdown early in the fourth quarter, and helped guide them to another with 8:52 remaining. But the freshman's incomplete pass on fourth-and-5 at the Oklahoma State 41 with 2:45 left turned the ball over, and a roughing-the-kicker penalty on D.J. Beshears after the defense had forced a punt allowed the Cowboys to run out the clock.
Cummings finished 5 of 10 for 75 yards and a touchdown. Crist was 10 of 22 for 136 yards.
The first quarter was about as ugly as the weather.
Under steel-gray skies and driving rain, Oklahoma State and Kansas managed to end four straight drives with failed fourth-down conversions. The Cowboys were stuffed at the line twice rather than let big-legged kicker Quinn Sharp take the field. The Jayhawks came up short on their first try and then failed to convert a faked field goal on their second.
The first lightning strike came with 44 seconds left in the first quarter, sending both teams to their locker rooms and fans scurrying for the concourse. Lightning continued to light up the sky for the next 40 minutes, and the delay stretched to 1:19 before the game resumed.
By that point, squeegees were needed to help remove standing water from the sidelines.
When the game resumed, Kansas made the first big play when Lubbock Smith picked off Walsh and returned the ball to the Oklahoma State 27. But three straight runs netted just 3 yards, and coach Charlie Weis elected to try again on fourth down - and failed again.
The nation's top-ranked offense finally got purring later in the quarter.
The Cowboys took possession near mid-field, and Walsh hit Tracy Moore for a 31-yard gain. Four plays later, Walsh scooted in from four yards out for a 7-0 lead.
Sharp added a 49-yard field goal with 49 seconds left in the half, but his 52-yard try as time expired left Oklahoma State with a 10-0 lead.
That was still the score when Oklahoma State took over with about 12 minutes left in the third quarter. On the first play from scrimmage, Walsh hit Charlie Moore on a quick pass play. Moore sprinted 72 yards down the sideline for the touchdown.
Sharp's field goal made it 20-0, and that's when Weis switched quarterbacks.
Cummings struggled on his first series, but he was sharp on his second try. He led Kansas 65 yards in nine plays, and his 21-yard touchdown toss to Jimmay Mundine with 10:52 left in the fourth quarter woke up the sparse crowd that had stuck around.
The crowd really came alive when the Jayhawks got the ball back.
Sims ripped off a 28-yard gain, a personal foul penalty moved the ball 15 yards more, and Sims meandered his way through the middle of the line for a 30-yard TD jaunt that made it 20-14.