DALLAS — If you believe in the multiverse theory, you walked out of the American Airlines Center on Saturday having experienced Houston’s worst possible timeline.

With 6:51 left in the first half, All-American point guard Jamal Shead jump-stopped in the lane before his ankle twisted.

The senior point guard, and Naismith Player of the Year finalist, stayed down in pain as Duke raced down the other end in transition. The Cougars’ “heartbeat”, as head coach Kelvin Sampson calls him, walked off the court via his own power but was assisted to the locker room and did not return to the game. Sampson said afterward that it was a “Grade 4 ankle sprain”.

Houston held a slim 14-10 lead at the time, but Duke took its first lead after Shead left at just under the three-minute mark. The Blue Devils never trailed again as they knocked off No. 1 seed Houston, 54-51, to advance to the Elite Eight on Sunday against NC State.

"I hate that it ended like this,” Shead said in the locker room post-game. “I wish I could have gotten back out there and been in the fight.”

When Shead went down, everyone inside the AAC immediately speculated that something severe had to be wrong. The play had transitioned to the other end of the floor, and Houston’s cog, who gutted out 45 minutes against Texas A&M less than a week ago, wasn’t on defense. His night ended with two points, three assists and two steals in just 13 minutes.

“He's a First Team All American, you don't have another one of those,” Sampson said. “You don't have the best defensive player in the Big 12. You don't have a guy that made all the big shots at the end.

The Cougars blitzed out to a 6-0 lead with Shead providing his usual two-way spark playing the passing lanes and initiating the offense. Duke head coach Jon Scheyer called timeout less than two minutes into the game to settle his team. Duke didn’t score until nearly five minutes in.”

“I doubt any team in America has – maybe Edey from Purdue – that means as much to their team as Jamal means to this team,” Sampson said. “There's just not another Jamal. He was the best player on the floor tonight. He's been the best player on the floor every game we've played this year except a few.”

Even in Shead’s absence, Duke couldn’t stretch the lead. Still, Houston’s offense took a hit without its leader and playmaker, but the bigger detriment was on defense. Shead’s arguably the best man-to-man defender in the nation and the best at playing the passing lane.

Without him, Houston shifted in and out of a zone defense during the second half.

That versatility was enough to frustrate Duke and keep the game within reach as LJ Cryer and J’Wan Roberts assumed primary scoring roles.

“Look, Shead is the ultimate competitor and winner, and I saw it firsthand,” Scheyer said. “We scrimmaged Houston last year, and just seeing what he does for their team and watching them on film, there's no replacement for him.

“But to be honest with you, your game plan can't change because you need to step your foot on the gas even more because when a guy like that goes out, you know, L.J. Cryer is going to do more and Sharp is going to look to go, and Roberts. I thought (Ramon) Walker hit a big three for them to cut it to three.”

Walker’s three with just under nine minutes to play was followed up by a Roberts hook in the lane that cut the deficit to one. But every time Houston crept closer, Duke had an answer.

All-American Kyle Filipowski hit a 3-pointer following that sequence to quell the run. He finished with a game-high 16 points.

“(Jamal’s) the head of the snake,” Roberts said. “He's the leader. When he goes, we go. My job when he is on and off the court is to lead by example and just try to take everybody else under my wing and just try to be the leader that I am.

“When he went down, it was hard to see, but we got confidence in each other. We know that we're going to stay together and play for him … The way I look at it, this is just deeper than basketball. It wasn't the outcome that we wanted, but I don't think nobody quit. I don't think nobody gave up. Everybody just kept fighting.”

The results are the results, and the history books will forever show Duke advancing to its 24th Elite Eight in program history. But even casual observers gotta wonder, ‘What If?’

What if Houston had its best player finish out the game? What if Jeremy Roach, who went scoreless until Shead left the game, couldn’t score his crucial 14 points? Does Houston get a chance to erase the demons of 1983 vs NC State? Do they win it all? What if?

“Well, it doesn't feel like a fair fight,” Sampson said. “You would have to take maybe two of theirs to equal one of Jamal. That's how good he was.”