STILLWATER, Oklahoma (Ticker) -- It's a good thing Oklahoma State coach Eddie Sutton is not a betting man.
Victor Williams converted two three-point plays during a key second-half run and scored 18 points as the 11th-ranked Cowboys pulled away for their 15th straight win, a 68-55 Big 12 Conference triumph over Iowa State.
"If someone would have told me in the beginning that we were going to win 15 games in a row, I would have bet my house and everything we have in the bank," Sutton said. "It is a big surprise to me. These guys have played better than I thought they could play."
Tony Allen added 15 points and Melvin Sanders chipped in 12 for Oklahoma State (17-1, 6-0 Big 12 South), which owns the longest winning streak in the country and has not lost since a 66-58 setback to the College of Charleston in the Great Alaska Shootout.
"I thought our defense was as outstanding as it has been," Sutton said. "You hold a team below 40 percent shooting and force 23 turnovers, you hold their best scorer to 1-of-10 shooting and six points."
Freshman Adam Haluska scored 15 points, but Jake Sullivan was held to six - 12 below his average - for Iowa State (11-6, 1-5), which has lost five of its last six games.
"They've got the reputation as having the best defense in the country and we knew coming in that it was going to be difficult," Cyclones coach Larry Eustachy said. "Our breakdown was turnovers. They are very athletic, quick and experienced. Nobody has a better coach, so they have a lot going for themselves."
Iowa State sliced an 11-point deficit to 29-25 at halftime, then got within two points early in the second half. The Cyclones still trailed just 42-38 before Williams fed Ivan McFarlin for a short jumper and converted his first three-point play.
Jackson Vroman answered with a basket for Iowa State, but Williams sent Sanders in for a fast-break layup, Andre Williams made 1-of-2 free throws and Victor Williams converted another three-point play. A baseline jumper by Cheyne Gadson capped the 13-2 spurt and gave Oklahoma State a 55-42 lead.
Victor Williams had one more three-point play, stretching the Cowboys' advantage to 62-45 with 4:43 left.
"We are going to get a lot of transition baskets with this team," said Sutton, whose squad faces third-ranked Texas on Saturday in a Big 12 showdown. "We are going to have a hard time Saturday, though, because T.J. Ford doesn't turn it over very often."
Andre Williams finished with eight points and 10 rebounds, but Oklahoma State missed 15-of-34 free throws and was outrebounded, 37-34.
"I think we looked past Iowa State," Andre Williams said. "They played hard and they did everything they could do to try to win the game. We came out looking to Saturday because we have a big game. And that's something we can't do in the future. We have to take each game as it comes."
Iowa State shot just 38 percent (21-of-55) and made just 13 trips to the foul line.
"Our confidence isn't shot, we just had a tough early season," Haluska said. I think if we can just get on a roll, we should still be able to win a lot of games in the conference and have some success in the Big 12 (tournament)."