The game of the day was in Buffalo, N.Y., as the No. 8 seed Wisconsin Badgers destroyed perhaps millions of brackets by upsetting the defending champion No. 1 seed Villanova Wildcats, 65-62, in an East Region second-round game on March 18.

Villanova guard Josh Hart, center, drives to the basket against Wisconsin forward Ethan Happ, left,  and forward Vitto Brown, right, with three seconds remaining in the second half of a second-round men's college basketball game in the NCAA Tournament, Saturday, March 18, 2017, in Buffalo, N.Y.  (AP Photo/Bill Wippert)

Villanova guard Josh Hart, center, drives to the basket against Wisconsin forward Ethan Happ, left, and forward Vitto Brown, right, with three seconds remaining in the second half of a second-round menโ€™s college basketball game in the NCAA Tournament, Saturday, March 18, 2017, in Buffalo, N.Y. (AP Photo/Bill Wippert)

The victory sent the Badgers (27-9) to the Sweet 16 for the fourth straight year, and marked the third time in four years that the Badgers have eliminated a No. 1 seed from the NCAA Tournament. The Wildcats (32-4) head home despite many picking them to defend their crown. 

Wisconsin pulled off the bracket-buster thanks in large part to the play of seniors Nigel Hayes and Bronson Koenig. Hayes scored a team-high 19 points with eight rebounds, while Koenig added 17 points. Hayes, who played in all three of Wisconsinโ€™s upset wins over No. 1 seeds, scored the game-winning shot over Villanova with 11 seconds left in the game. 

Wisconsin guard Bronson Koenig (24) takes a jump shot while defended by Villanova guard Donte DiVincenzo (10), guard Jalen Brunson (1) and forward Kris Jenkins (2) during the second half of a second-round men's college basketball game in the NCAA Tournament, Saturday, March 18, 2017, in Buffalo, N.Y. (AP Photo/Bill Wippert)

Wisconsin guard Bronson Koenig (24) takes a jump shot while defended by Villanova guard Donte DiVincenzo (10), guard Jalen Brunson (1) and forward Kris Jenkins (2) during the second half of a second-round menโ€™s college basketball game in the NCAA Tournament, Saturday, March 18, 2017, in Buffalo, N.Y. (AP Photo/Bill Wippert)

โ€œAll of those games weโ€™ve been the underdog,โ€ Hayes told reporters after the game. โ€œYou have all types of ranking systems, statistics. The thing with all those algorithms is they canโ€™t calculate heart, will to win, toughness, desire. And thatโ€™s the thing we have.โ€

Villanova senior guard Josh Hart scored a team-high 19 points in the loss; senior forward Kris Jenkins, who made the game-winning buzzer-beater in last yearโ€™s national championship game, made just 2-of-9 shots against Wisconsin for a mere six points. 

Wisconsin will play Florida in the Sweet 16 on March 20. 

In other NCAA action: 

West Region

  • No. 1 Gonzaga defeated No. 8 Northwestern, 79-73
  • No. 2 Arizona defeated No. 7 Saint Maryโ€™s, 69-60
  • No. 4 West Virginia defeated No. 5 Notre Dame, 83-71
  • No. 11 Xavier defeated No. 3 Florida State, 91-66

South Region

  • No. 4 Butler defeated No. 12 Middle Tennessee, 74-65