Jamaal Franklin posted 21 points and eight rebounds as San Diego State took a 70-55 win over Oklahoma in the second round of South Region action on Friday.
James Rahon had 17 points while Chase Tapley added 10 points for the seventh- seeded Aztecs (23-11), who also got seven points and 11 rebounds from Deshawn Stephens.
"I'm very proud of how we competed. We talked at halftime of making sure we came out and prioritized how we guarded," San Diego State coach Steve Fisher said. "We have a little bit of an MO where our second-half defense doesn't match our first half, and today our second half defense was superior to our first half, and that's how we won. We found a way to win."
San Diego State, which is in the tournament for a fourth straight year, will next play Florida Gulf Coast, which turned in an upset win over Georgetown, on Sunday.
Romero Osby scored 22 points with eight rebounds to lead the 10th-seeded Sooners (20-12), who were in this event for the first time in four seasons. Amath M'Baye had eight points and four boards in the loss.
"It was a tough loss. San Diego State is a very good basketball team," said Oklahoma coach Lon Kruger. "At a critical time in the ballgame they were a little quicker to loose balls, a little tougher driving and kicking and making plays that they finished at the rim."
Holding a two-point lead, San Diego State was able to create some distance with the long ball as Franklin and Rahon hit triples, sandwiched by a Osby bucket, for a 48-42 lead with 13 minutes to play.
The Sooners scored the next six points with Cameron Clark's layup tying the game, but Tapley answered with a layup to spark an 8-0 run with Stephens' tip- in giving the team a 56-48 advantage with eight minutes to play.
After a pair of failed possessions from each side, Osby hit a triple to get Oklahoma back in it, but Rahon followed with a long ball of his own at the other end.
Buddy Hield then missed a 3-pointer for Oklahoma and San Diego State followed with a pair of misses at the other side.
Following another missed trey by Oklahoma, Rahon missed a layup, but Stephens came down with the offensive board and Franklin put in a jumper for a 10-point lead with 4 1/2 minutes to play.
Each team then had several failed possessions and J.J. O'Brien hit a pair of free throws with just over two minutes to play for a 63-51 advantage.
Amath M'baye countered with a layup, but the Aztecs hit their free throws the rest of the way to advance.
It was a tight first half through the first several minutes until Oklahoma ripped off a 12-0 run with a Steven Pledger 3-pointer giving the team a 23-14 lead with under 10 minutes to play.
San Diego State used a 10-3 run later in the half to cut into its deficit with a Rahon jumper making it a one-point game.
Isaiah Cousins countered with a 3-ball and Rahon's bucket at the other end was the final points of the half as the Sooners took a 33-31 edge into the break.
San Diego State shot 42.9 percent from the floor, including a 6-of-15 click from behind the arc, while Oklahoma made 39.7 percent of its attempts and was just 5-for-21 from long range ... It was the first meeting between these two schools since 1975. Oklahoma had won all three of the previous matchups ... The Aztecs managed 40 rebounds, compared to just 29 by the Sooners.