Connecticut (23-9) advanced to meet Texas or Purdue next Friday in San Antonio. Texas and Purdue will meet Sunday in Birmingham. The Huskies advanced to the regionals for the seventh time in their last eight NCAA Tournament appearances.
"We had a lots of ups and downs this season," Okafor said. "Right now, we're reaching a high point."
Stanford (24-9) outran Connecticut in the first half, building a 44-40 edge at intermission as Julius Barnes made four three-pointers and scored 16 points.
But the Huskies emphasized Okafor in the second half and the 6-9 center responded with the team's first six points. His layup with 13:13 remaining gave Connecticut the lead for good and triggered an 11-4 tear for a 67-60 advantage.
"I was coming out tentative, wasn't my usual bounce self," Okafor said. "I dug down deep and brought it out."
Okafor also had 15 rebounds to help Connecticut control the glass with a 43-33 edge. The Huskies came up with 17 offensive rebounds.
"Had we been able to withstand the physical onslaught at the start of the second half, we would have been able to stay in it and control the tempo," Stanford Coach Mike Montgomery said.
Ben Gordon scored 29 points and was noticeably more aggressive than in Thursday's first-round win over Brigham Young. At one point, Coach Jim Calhoun took him out of the game after Gordon passed up a shot and the effect was noticeable.
"Sometimes I get caught up in making my teammates better," Gordon said. "I listened to what the coaching staff had to say. When I got back in, I tried to correct those things."
"Ben came out on fire," Barnes said. "Ben was not only hitting threes, he was penetrating and getting easy shots."
The key to the second half was Connecticut's stingier defense on the perimeter as it limited the touches of Barnes and Matt Lottich. Stanford had one three-pointer in the second half after nailing seven over the first 20 minutes.
Stanford shot just 39 percent in the second half. Lottich and Josh Childress combined to make five of 21 shots for the game.
"Josh and Lottich could have shot the ball better," Montgomery said. "Defensively, they decided not to let our shooters shoot the ball (in the second half)."
Stanford climbed within 67-63 on a layup by Justin Davis with 5:11 remaining. But Gordon knifed inside and found Mike Hayes for a layup for a six-point cushion.
After a free throw by the Cardinal's Rob Little, Gordon fed freshman Rashad Anderson for a 3-pointer and added a runner in the lane for a 74-64 lead with over two minutes left.
"I thought we had a better mental approach," Gordon said. "We were keying in and more focused for the game."
Part of Connecticut's focus may have been because of Calhoun's decision to arrive in Spokane late Monday night. The Huskies were thought to be at a disadvantage because of the cross-country trip.
"This is a pretty good site to go to," Calhoun said. "People are enthused about the game, whether you're from Connecticut or not. Spokane is really a terrific place."
Barnes scored 24 points in his final game and Justin Davis added 19 and 10 rebounds. The Cardinal lost in the second round for the third time in four years.
The Huskies are 4-0 all-time against the Cardinal.