Vote: What's the biggest upset so far in the NCAA tournament?

The first days of the NCAA tournament may have been quiet, but the madness in March has started to reveal itself.

In the second round on Saturday, No. 1 overall seed and defending national champion Villanova was knocked out by eighth-seeded Wisconsin. Then, 11th-seeded Xavier dominated third-seeded Florida State.

The Michigan Wolverines' hot streak continued, as they topped second-seeded Louisville to win their seventh straight game. Preseason No. 1 Duke, a 2-seed, was stunned by seventh-seeded South Carolina, and the Gamecocks controlled most of the contest.

What do you think has been the biggest upset thus far in the NCAA tournament? Vote now!

No. 1 seed North Carolina was on the ropes versus eighth-seeded Arkansas but escaped with a victory in the closing moments. Kentucky, Oregon and Baylor were also in dogfights on Sunday but found ways to win.

With 16 teams remaining, which ones do you believe have emerged as the favorites to win the title?

The Sweet 16 will take place on Thursday and Friday, while the Final Four will be decided by the Elite Eight matchups over the weekend.

-- Josiah Turner