Forte, a 5-foot-11 shooting guard, made 4 of 7 3-pointers and matched a career high with five rebounds for the Cowboys, who claimed their second win over a ranked opponent this season.
Michael Cobbins had six points, a season-high 11 rebounds and matched a career high with five blocks. Anthony Hickey had eight points and a career-high 10 assists and freshman Tavarius Shine added a season-high 11 points for the Cowboys (14-6, 4-4 Big 12), who will host No. 24 Oklahoma on Saturday.
Lester Medford scored 13 points, Taurean Prince added 12 and Rico Gathers added 11 points and 11 rebounds for Baylor (15-5, 3-4), which had won four of five. Baylor shot just 34.5 percent from the field and posted a season-low point total.
Baylor went on an 11-0 run early to go up 13-6. Oklahoma State rallied, as threes by Forte and Hickey highlighted a 9-0 run that put the Cowboys up 23-17 and forced a Baylor timeout. The Bears went more than four minutes without scoring.
The Cowboys held Baylor to 32 percent shooting in the first half and led 30-21 at the break.
Jeff Newberry's pump fake, drive and two-handed jam put the Cowboys up 32-25 early in the second half. Another three by Forte pushed Oklahoma State's lead to 10.
Baylor hung around, but Oklahoma State hung on. Hickey penetrated and found an open Forte for 3 with four minutes remaining to stretch the Cowboys' lead to 10.
Baylor: Gathers had 25 points and 28 rebounds against Huston-Tillotson on Jan. 21. ... Baylor made just 3 of 6 free throws and had three assists in the first half.
Oklahoma State: The Cowboys went 5-for-10 from 3-point range in the first half. ... Forte increased his career scoring total to 1,136 points. He passed both Mario Boggan and Chianti Roberts on the Oklahoma State career scoring list and now ranks 30th.
Baylor: Hosts Texas on Saturday.Oklahoma State: Hosts Oklahoma on Saturday.
------Follow Cliff Brunt on Twitter: www.twitter.com/CliffBruntAP.