Houston guard Marcus Sasser celebrates during the Cougars’ regional final against Oregon State on Monday in Indianapolis. Sasser scored 20 points and Houston won, 67-61. MIchael Conroy/Associated Press

INDIANAPOLIS — Kelvin Sampson stood atop a ladder and yanked loose the remnants of the net from the rim. He turned toward the red-clad Houston fans and started pumping his right fist, the net clutched in that hand the entire time.

Years of building a once-proud program back to prominence, of putting together a formula that was about way more than flashy offense – it all led to this breakthrough moment for Sampson and the Cougars.

Yes, Houston is going back to the Final Four for the first time since the famed “Phi Slama Jama” era after Monday night’s 67-61 win against Oregon State.

“I always thought we could,” Sampson said, “but we had to climb the ladder.”

It was never supposed to be easy to get the second-seeded Cougars (28-3) back into the Final Four for the first time in 37 years, Sampson said. And his team proved him right, blowing a 17-point lead before preventing the 12th-seeded Beavers from adding one more surprising result to a Midwest Region bracket beset by upsets.

Quentin Grimes hit a 3-pointer with 3:21 left to break a 55-all tie, making a shot from near the top of the arc that finally steadied the Cougars. And Houston knocked down enough free throws late while holding Oregon State without a basket during a critical 3 1/2 minutes.

That sent the Cougars on to the national semifinals to face Baylor.

Houston shot 29% after halftime and 32% for the game. Yet the performance exemplified the program’s rugged defense-first identity, which had carried the Cougars as far as the Sweet 16 once before in Sampson’s first six seasons.

“This is one of the greatest accomplishments I’ve been around,” Sampson said. “And I have this group of players and this staff … to thank for it. I’m glad they let me go along on the ride with them. It’s been a fun ride with this group.”

Marcus Sasser scored 20 points to lead Houston, while Grimes added 18. Fittingly, it was DeJon Jarreau – the American Athletic Conference’s defensive player of the year – led the effort that stymied Oregon State star Ethan Thompson.

Jarreau finished with 10 points, eight rebounds and eight assists, two days after flirting with a triple-double and shutting down Syracuse’s Buddy Boeheim in the Sweet 16.

Maurice Calloo scored 13 points to lead Oregon State (20-13), which was vying to become the worst-seeded team ever to make a Final Four – and to extend a remarkable postseason run for a team that was picked to finish last in the Pac-12. The Beavers dug a 34-17 hole at halftime, then climbed all the way back only to see Grimes put the Cougars back in front.

“It was right there within our grasp with the effort we showed in the second half,” Oregon State Coach Wayne Tinkle said. “Really proud of this group. We got every single ounce out of them.”

(1) BAYLOR 81, (3) ARKANSAS 72: Baylor reached the Final Four for the first time in 71 years, getting 22 points from MaCio Teague and a dominating defensive performance from Davion Mitchell to beat Arkansas.

The South Region final was a reunion of former Southwest Conference programs aiming to join another (Houston) in the Final Four.

The top-seeded Bears (26-2), which had not been able to get over the Elite Eight hump in two previous tries under Coach Scott Drew, appeared to be barreling toward a blowout.

The Razorbacks (25-7), though, revved up after some early sputtering, trimming an 18-point lead down to four.

Baylor ran away from there, as Arkansas missed 12 straight shots and Teague hit a pair of 3-pointers to put it out of reach.

JD Notae and Davonte Davis had 14 apiece for the Razorbacks, who came up one game short of their first Final Four in 26 years.