Arizona's upset loss to Buffalo busts brackets across America

Biggest upset ever?

Not even close, though 94.8 percent of Yahoo users picked Arizona. Back in 2014, Mercer beat third-seeded Duke, picked by 97.6 percent, and in 2013 Florida Gulf Coast, a 15-seed, took down Georgetown, picked by 98.1 percent of users that year.

The other upset of the day

Early on Thursday, 11-seeded Loyola Chicago took out Miami (Fla.) and with it 63.6 percent of users. But even that loss still left nearly 400,000 perfect brackets remaining.

The biggest what-if of the day

Thirteen-seed UNC-Greensboro had 4-seed Gonzaga on the ropes in the second half. The Zags were able to pull it out, 68-64. Had UNC-Greensboro won, well, this would have been the biggest upset of the day, as 96.5 percent picked the Zags.

More March Madness coverage from Yahoo Sports:
• Cinderella’s upset bid ends on physics-defying miss
• Loyola Chicago stuns Miami on last-second shot for upset win
• Oklahoma wastes Young’s heroics in NCAA tournament
• NCAA player winks at NBA legend after insane shot
• Loyola’s 98-year-old nun loved buzzer-beater