LeBryan Nash scored 21 points as Oklahoma State sent rival Oklahoma to an 0-3 Big 12 Conference start, winning 72-65 Monday night in Stillwater.The Cowboys (9-7 overall, 2-1 Big 12) used a 14-2 run to end the first half and led 35-22. In the second half, the lead grew to as many as 17 on Nash's tip-in with 12:26 remaining.But, the Sooners didn't go away quietly, scoring eight straight to cut the lead to single digits on Carl Blair's 3-pointer with 10:25 to play.OSU responded with a 10-2 run to extend the lead back to 17, a lead that, despite a furious run over the final few minutes, would be too much for the Sooners to overcome.Joining Nash in double figures for Oklahoma State was Keiton Page with 18 and Brian Williams with 13. Michael Cobbins fell one point short of a double-double, scoring 9 to go with ten rebounds.Blair led the Sooners (10-5, 0-3) with 20 points and 10 rebounds off the bench. Romero Osby also had a double-double, scoring 18 points and grabbing ten boards. Andrew Fitzgerald scored 12.Oklahoma State faces its toughest test of the season so far when they return to play Saturday at fourth-ranked Baylor. OU will try to notch its first conference win when they host 18th-ranked Kansas State.