And then there were 1s.

With wins by Houston and Auburn on Sunday, next weekend’s Final Four will have all four No. 1 seeds for the second time in NCAA Tournament history.

The only other time since seeding began in 1979 was in 2008, when Kansas, Memphis, UCLA and North Carolina went to the Final Four — in San Antonio, no less.

This year also marks the first time higher seeds went 12-0 in the Sweet 16 and Elite Eight, capping a year of chalk that ends on the Riverwalk.

Houston gave Tennessee a lesson in defensive dominance, shutting down the Vols for a 69-50 win to reach the Final Four for the seventh time. The Cougars held Tennessee to 15 first-half points and 29% shooting overall, including 5 of 29 from 3.

Auburn survived an injury scare to star forward Johni Broome and Michigan State’s gritty style to pull out a 70-64 win in the South Region final. Broome left the court with a right elbow injury and returned a few minutes later to finish with 25 points and 14 rebounds. Coach Bruce Pearl’s Tigers are in the Final Four for the second time, having gotten there in 2019.

Florida was the first team to reach the Final Four with an 84-79 win over Texas Tech in the West Region final on Saturday. Duke followed by shutting down high-flying Alabama for an 85-65 win in the East Region final.

That sets up an all-SEC national semifinal between Florida and Auburn, with Houston facing Duke in the other.

May the best 1 win.

Broome’s elbow status >> Broome finished the South Region final with 25 points, 14 rebounds and a thick wrapping on his ailing elbow.

“I didn’t get any diagnosis,” coach Bruce Pearl said. “When Johni came out of the locker room, I had not talked to the doctor. I just said, ‘Are you good to go?’ He said, ‘I am,’ so I said, ‘Get your (butt) in there.’ ”

Broome, the top-seeded Tigers’ leading scorer and rebounder, exited after he leaped above the rim attempting to block a drive to the basket by Frankie Fidler of Michigan State.

Fidler missed the shot, and Broome’s elbow bent at an ugly angle when he put down his right hand, trying to brace his fall.

Broome stayed down on the court, grimacing and holding his elbow, while a Spartans trainer signaled hurriedly for the Auburn staff at the other end to check on the player.

The 6-foot-10 senior forward untucked his shirt heading off the court and went to the locker room with 10:37 left in the second half and the Tigers leading 50-40.

The AP’s SEC player of the year, Broome returned with 5:39 left and Auburn still holding a 10-point edge, drawing a huge roar from the pro-Tigers crowd at State Farm Arena.

The crowd really erupted when he swished a 3-pointer to make it 60-48.

“All the glory to God for allowing me to be healthy,” Broome said. “We have a great support staff. They checked the arm out and doc said, ‘There’s nothing wrong. You’re good.’ At that moment, I just wanted to help my teammates. If it was coming back out and playing, hitting my shots and grabbing rebounds, I was going to do it.”

Pearl said he should know more today about Broome’s status for the Final Four, though it certainly appears he will be ready to go. The coach described the injury as “maybe a slight hyperextension.”

Stingy D defines Houston’s run >> Houston’s relentless, harassing defense had Tennessee’s shooters dancing around.

Now, the Cougars are two-stepping it back to Texas.

L.J. Cryer finished with 17 points, Emanuel Sharp scored 14 of his 16 points in the second half and the nation’s stingiest defense delivered a historic NCAA Tournament performance, leading top-seeded Houston past second-seeded Tennessee 69-50 for the Midwest Region title and its seventh trip to the Final Four.

Next up is Cooper Flagg and five-time national champion Duke on Saturday in San Antonio, just a 3 1/2-hour drive from Houston’s campus. First, the Cougars wanted to savor the journey they took to this net-cutting celebration, one that failed to materialize each of the past two seasons when they were eliminated in the Sweet 16 as a No. 1 seed.

“It’s a good feeling knowing what we’ve been through,” Sharp, the region’s most outstanding player, said of Houston’s first Final Four appearance since 2021. “A lot of people doubted us.”

The Cougars (34-4) broke the school’s single-season record for wins, extended the nation’s longest active winning streak to 17 games and gave coach Kelvin Sampson a third chance to reach his first national championship game.