STILLWATER, Okla. (AP) -- When Oklahoma's 3-point shooters are on their game, Courtney Paris can afford to slow down her prolific scoring pace.
Leah Rush scored 15 points, Chelsi Welch added 13 and No. 16 Oklahoma used a 3-point barrage to beat Oklahoma State 85-51 on Saturday.
The Sooners, who matched their season low with two 3s in a 75-71 loss to Ohio State on Monday, hit 13-for-28 to equal their best performance of the season against Iowa State in their Big 12 opener on Jan. 4.
"Today we had a combination of playing really, really hard and the ball going in the basket, particularly from 3-point range," Oklahoma coach Sherri Coale said. "When you do those two things together, scores can blow up pretty quickly."
Seven different Sooners hit 3-pointers, and five had at least two apiece. Welch, who was 3-for-6, had the most.
"When they're hitting their 3s like that, they're going to be tough to beat," Oklahoma State coach Kurt Budke said.
Paris tied her season low with 12 points, but the Sooners got plenty of scoring elsewhere. Laura Andrews had a season-high 12 points off the bench and Britney Brown and Kendra Moore had 10 apiece.
Paris added 16 rebounds for her nation-best 14th double-double. She's on pace to break Oklahoma's school records in scoring, rebounding and several other categories.
"I thought she was willing to give up her offense to get everybody else involved, and that's the sign of a true star player," Budke said.
The first-year Oklahoma State coach said he thought the Cowgirls didn't stand a chance if they let Paris get 30 points and 20 rebounds, so they focused their defense on the 6-foot-4 freshman who was last year's national high school player of the year.
"We thought, 'We have to make them beat us from the outside,' and they did," Budke said.
Oklahoma (13-4, 3-0 Big 12) is shooting 39.5 percent (94-for-238) from 3-point range in its 13 wins and 17.6 percent (12-for-68) in its four losses.
"A lot of it's about rhythm," Welch said.
Oklahoma started the second half with seven straight points on two putbacks by Paris and a 3-pointer by Erin Higgins to lead 51-26.
The Sooners led by at least 21 points the rest of the way, and their advantage reached 69-40 after Paris had two baskets and Andrews hit two 3-pointers during a 10-2 burst.
Coale pulled the last of her starters with 4:36 remaining.
Shaunte' Smith scored 15 to lead Oklahoma State (6-9, 0-4), and Brisa Silva had 10. Whitney Pegram, who had been averaging 18 points, matched her season-low with six points on 3-for-11 shooting.
The Cowgirls have lost 14 in a row in the Bedlam series and 11 straight to Big 12 opponents.
Paris scored back-to-back baskets to spark a 17-5 run as Oklahoma pulled away early in the first half. Welch scored eight points -- including a pair of 3-pointers -- during the run and Ashley Paris' basket inside gave the Sooners a 27-14 lead.
Oklahoma widened its lead to 44-26 by halftime as Oklahoma State matched its entire output from a 57-26 loss to No. 5 Baylor on Wednesday.