Which team will spring a March Madness upset in the Elite Eight?

The regional finals are set, and the Pac-12 has single-handedly spiced up the Elite Eight with some double-digit upsets in the Sweet 16.

No. 12 Oregon State and No. 11 UCLA are the only double-digit seeds left in the 2021 NCAA Tournament, as the cream has otherwise risen to the top in the other portions of the bracket.

Three No. 1 seeds remain, but are any of them vulnerable? Will the chaos continue? Could we see an unprecedented, longshot Final Four? Weigh in and get ready to watch more madness.

#12 Oregon State vs. #2 Houston

When you consider the Beavers needed to win the Pac-12 Tournament just to earn a berth into the NCAA Tournament (Oregon State didn't have a worthy résumé at the time), it puts their run in an even more impressive light.

They have won six straight all-or-nothing elimination games, including an overtime win over UCLA in the first round of the Pac-12 Tournament, and a two-point win over Colorado in the conference title game.

The Beavers haven't been as challenged in the Big Dance, as their average margin of victory against No. 5 Tennessee, No. 4 Oklahoma State, and No. 8 Loyola Chicago is 10.3 points.

Houston absolutely dismantled No. 11 Syracuse in the Sweet 16, but needed a late implosion from No. 10 Rutgers to get there.

The Cougars play tough defense, but the Beavers haven't blinked against any competition yet in the NCAA Tournament.

Can Oregon State be the first No. 12 seed to advance to the Final Four?

#3 Arkansas vs. #1 Baylor

No. 5 Villanova gave Baylor a scare in the first half, but the talented Bears overcame a 30-23 halftime deficit and pulled away to a relatively comfortable 62-51 victory.

Arkansas didn't have it so easy. The Razorbacks got past No. 15 Oral Roberts by the skin of their teeth Saturday, and the Golden Eagles even got a good look to win it at the buzzer.

And that wasn't Arkansas' first close call. The Hogs also got past No. 6 Texas Tech, 68-66, in the second round.

Were those results indicative of Arkansas' toughness and grit, or could the Razorbacks be playing down to their competition?

Regardless, they'll have to play up to the Bears if they want to get to the Final Four.

#6 USC vs. #1 Gonzaga

If you view the NCAA Tournament performances for each team as a whole, the argument could be made that Gonzaga and USC have been the most impressive teams.

The Zags have been an efficient, devastating machine, so much so that No. 5 Creighton looked like a junior varsity squad Sunday.

The point can be made that Gonzaga hasn't played a team of USC's caliber since at least December, but USC hasn't played a team with Gonzaga's talent all season. 

Matchups will be key. USC is one of the longest teams in the nation, led by 7-footer and future lottery pick Evan Mobley.

But Gonzaga has the smooth, unflappable guard play of Jalen Suggs (another likely lottery pick), along with a bevy of other offensive weapons.

As far as future NBA talent goes, this might be the game of the week.

Can anyone stop the Zags' runaway train?

#11 UCLA vs. #1 Michigan

The way UCLA has played in the NCAA Tournament, from the tip against Michigan State in the play-in round, you have to admit the Bruins have a puncher's chance against anyone.

UCLA has displayed the toughness we've come to expect from Mick Cronin's teams, and appear to even relish the fight.

There are certainly positives to draw from UCLA's victory overtime over No. 2 Alabama in the Sweet 16, most notably that the Bruins were able to persevere after the loss of their best player, Johnny Juzang, who fouled out with 2:26 left in regulation.

But it's hard to ignore the context that Alabama was abysmal from the free-throw line. The Tide hit just 11 of their 25 attempts. If Alabama was even moderately successful at the line, it would have won in regulation.

Michigan put in its best performance of the tournament in the Sweet 16 and smothered No. 4 Florida State.

UCLA might have grit, but Michigan is no slouch in that department, either. Get ready for a grind-it-out battle for all 40 minutes.