KANSAS CITY, Mo. -- Andrea Riley missed 17 shots in a row during one stretch Friday -- and her coach still wanted her to keep firing away.
Oklahoma State coach Kurt Budke has seen her act before.
The streaky Riley scored 43 points to set the Big 12 tournament single-game record for the second straight game and Oklahoma State (No. 21 ESPN/USA Today, No. 20 AP) upset No. 14 Iowa State 62-59 in the quarterfinals Friday.
Riley made 6 of her first 7 shots, then missed those 17 in a row before warming up again late in the game to carry the seventh-seeded Cowboys into a Saturday semifinal against Baylor or Oklahoma.
Riley also became the Big 12's career leading scorer and set the conference's single-season scoring record.
"In the game of basketball, it's always up and down, and sometimes you're not going to stay hot," Riley said. "So I had to listen to my coaches and teammates who continued to be in my ear, and I'm glad and appreciate how much they support me and how they have so much confidence in me. They really made me push in the end."
Riley scored 19 of the Cowgirls' last 23 points to hold off Iowa State, which came back from a 15-point first-half deficit to lead.
Riley finished 16-of-44 from the field, with most of her shots coming on pull-up jumpers in and around the lane as Iowa State packed in its defense.
"I never think about how many times I shoot," Riley said. "Coach Budke told me if they're going to give you that shot, I don't care if you take 50 shots -- and I got close."
Said Budke: "That's true. That's what I told her."
Anna Prins had 15 points, Kelsey Bolte 12 and Whitney Williams had 11 for Iowa State.
Riley, who scored 37 points against Kansas on Thursday, came into the game tied with Oklahoma's Courtney Paris as the league's career scoring leader. Riley now has 2,772 points.
Riley has 846 points for the season, breaking the conference mark she set two years ago.
Riley hit jumpers to tie it at 50-all and to put the Cowgirls (23-9) up 54-50, and she drove to the basket to make it 58-55 with 45 seconds left.
She hit four free throws in the last 13 seconds to hold off the second-seeded Cyclones (23-7).
"There is nobody more valuable to their team than what she's done the last four years for resurrecting this program," Budke said. "I know we have a deserving MVP in this league [Nebraska's Kelsey Griffin], but there is no way I would vote for anybody else but Andrea."
The loss ended the Cyclones' streak of making it past their first Big 12 tournament game every year since 2003. Riley hit three 3s to help Oklahoma State get out to a 19-7 lead.
Iowa State coach Bill Fennelly said he figured Riley would be a "volume shooter," but that his team would have had a chance to win if it had shot better than 33 percent.
"We held Oklahoma State to 62 points. I don't care who scores," he said. "There is no way you're going to stop her from scoring. She's a great player and certainly someone who has had a great career, and certainly someone that all of us will be glad to see graduate."
When the 6-foot-7 Prins knocked down a 3-pointer at the top of the key, Iowa State led for the first time at 28-27.
The teams went back and forth from there, with Iowa State taking its last lead at 50-48 with 5:39 to play.
Iowa State's All-Big 12 point guard, Alison Lacey, didn't play because of her continuing battle with a bronchial illness. She missed last week's 78-70 loss at Oklahoma State and was on the floor for just two seconds last weekend against Colorado so she could have a ceremonial start on Senior Day.
Fennelly said he expects Lacey to be ready to play in the NCAA tournament.