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After a calm start in the round of 64, lower seeds officially turned the NCAA tournament into March Madness in the second round. The No. 1 overall seed and two No. 2 seeds took early exits. 

We're going to crown a new tournament champion thanks to No. 8 Wisconsin shocking Villanova. Two legendary coaches in Mike Krzyzewski and Rick Pitino lost to No. 7 seeds, who wanted it more on Sunday.

Without the top two seeds in the East Region, which program will rise to the occasion to reach the Final Four? Will the remaining No. 1 seeds stay alive until April?

The graphic below displays the Sweet 16 matchup dates. Who's punching their ticket to Glendale, Arizona?

East Region Winner: Florida

According to ESPN Fantasy Sports, most East Region brackets went up in flames after Duke's loss to South Carolina:

Among the four teams left in the region, Florida should emerge as the underdog Final Four team simply because most bracket challengers handed the spot to Duke or Villanova.

The Gators won both their contests as the higher seed, and they held Virginia to 39 points in the second round. The Cavaliers don't have a track record for scoring points, but Florida deserves tremendous credit for locking down on the defensive end.

Going into the tournament, Florida didn't look too sharp. It lost consecutive games to Vanderbilt, a No. 9 seed who didn't win a game in the Big Dance. A victory over East Tennessee State isn't much to brag about, but forwards Devin Robinson and Justin Leon logged double-doubles against the Cavaliers largely due to their opponents' poor shooting.

Florida shouldn't have an issue limiting Wisconsin's underwhelming offense on Friday. In fact, none of the teams left in the East Region rank within the top 150 in points scored per game, which bodes well for the Gators.

South Region Winner: UCLA

On Sunday, UCLA cruised through the first half against Cincinnati and quickly turned up the heat after halftime. Guard Lonzo Ball came out of the locker room with a scorching hand that went 4-of-7 from three-point range. Meanwhile, freshman forward TJ Leaf and junior center Thomas Welsh feasted in the paint.

After light lifting in the first two rounds, the Bruins square off against a college basketball blue blood in Kentucky, who imposed its physical will on Wichita State in the second round. The Wildcats thrive on free throws and second-chance scoring opportunities. They rank No. 1 in free-throw attempts and No. 7 in total rebounds. 

UCLA's spread-out play style should prevent Kentucky from clogging the passing lanes and using physicality to wear on prominent scorers. Furthermore, the Bruins don't leave much margin for error. They shot 50 percent or better from the field in their two tournament victories.

North Carolina will provide a tougher challenge as the nation's leading program in total rebounds coupled with the ability to keep pace on the scoreboard. Nonetheless, the Bruins have the frontcourt to challenge the Tar Heels in a similar fashion to Arkansas on Sunday.

Midwest Region Winner: Michigan

Despite finishing strong, Michigan's star guard Derrick Walton Jr. struggled through most of the game against Louisville. Forward Moritz Wagner kept the Wolverines in the contest, and forward D.J. Wilson closed the deal with his clutch free-throw shooting. 

Michigan boasts a legitimate trio. Each player has the skills to put the team on his back for a victory. The Wolverines faced adversity within the first two rounds. The win over Oklahoma State turned into a high-pressure scoring fest. On Sunday, Michigan had to show resolve as its standout player shot below 25 percent for the game.

Wagner and Wilson should be able to take advantage of Oregon on the inside or outscore them in a fast-paced game. The real test will happen against a rejuvenated Kansas team. The Jayhawks will finish with more highlights, but the Wolverines' scoring prowess will punch their ticket to the Final Four.

West Region Winner: Arizona

On Saturday, Arizona nearly became a headline as a higher seed that exited the tournament a few rounds too early. Saint Mary's led at halftime and continued to push the Wildcats to their maximum limits. Then, 7-footer Lauri Markkanen dominated the paint on both ends of the court. He finished with a double-double, two blocks and shot 9-of-10 from the free-throw line. 

No one receives credit for effort or moral victories in the NCAA tournament, but the Gaels earned respect from their opponents and ESPN college basketball analyst Jay Williams:

Skeptics will look at Arizona's matchups and question if either victory provided a challenge or a dose of adversity. Compared to the other projected Final Four teams, it's a valid criticism.

Nonetheless, we've yet to see guard Allonzo Trier at his best. He's shooting 8-of-21 from the field through the first two rounds. He's due for a breakout game against Xavier, the lowest seed remaining in the tournament. 

In the following round, the Wildcats should be able to push the pace and force Gonzaga to take more three-point shots—something the team is not accustomed to doing—to close scoring gaps.

Stats provided by Sports Reference, unless otherwise noted.