The Sweet 16 includes teams from the Atlantic 10, Horizon League, Ivy League, Missouri Valley Conference and West Coast Conference.
And there's one team from the Pac-10, which only looked like a mid-major league this season.
The final day of the first weekend of the 2010 NCAA tournament was as unpredictable as the first three, as Sunday delivered yet another upset and two more buzzer-beaters.
Now the tournament takes a three-day hiatus before regional semifinals begin Thursday in Salt Lake City and Syracuse, N.Y. College basketball fans can probably use a break after watching one of the most entertaining opening weekends in NCAA tournament history.
And maybe they'll stop celebrating by then on the Cornell University campus in Ithaca, N.Y. On Sunday, the 12th-seeded Big Red became the lowest-seeded team to reach the Sweet 16 this year after blasting 4-seed Wisconsin 87-69 in an East Regional second-round game in Jacksonville, Fla. Outside first-round games, it is the second-largest margin of victory ever for a team seeded 12th or lower.
Cornell becomes the first Ivy League team to reach the regional semifinals since Penn advanced to the 1979 Final Four, where the Quakers lost to Michigan State and Earvin "Magic" Johnson in the national semifinals. After going 4-63 all-time against teams ranked in The Associated Press Top 25 poll, the Big Red upset No. 12-ranked Temple and No. 16-ranked Wisconsin in their last two games.
And for the second straight game, one of the country's best defenses had no answer for Cornell's one-two punch of Louis Dale and Ryan Wittman, who combined to score 50 points. The Badgers came into the game ranked fourth in the country in scoring defense (56.2 points per game) and didn't allow more than 50 points in 14 of their games.
Cornell shot 61.1 percent, the highest field goal percentage the Badgers have allowed in the nine-year tenure of coach Bo Ryan.
"We've got eight seniors on this team, and we want to take this ride as long as we can, because after this it's just nothing but babies and memories, so we'll just keep going," Dale told reporters on Sunday.
The Big Red play No. 1-seed Kentucky in Thursday's East Regional semifinals in Syracuse, N.Y., which is about a one-hour drive from the Cornell campus. No. 2-seed West Virginia, a 68-59 winner over 10th-seeded Missouri in Buffalo, N.Y., on Sunday, plays 11th-seeded Washington in the other regional semifinal in Syracuse.
Michigan State, which has become a Sweet 16 staple under coach Tom Izzo, will have to travel a little farther to St. Louis for Friday's Midwest Regional semifinals. But the Spartans' journey there is nearly as remarkable as Cornell's.
In a game that saw four lead-changes in the final 39 seconds, 5th-seeded Spartans beat 4-seed Maryland 85-83 on Korie Lucious' 3-pointer at the buzzer in a second-round game in Spokane, Wash., on Sunday. Michigan State won after losing star guard Kalin Lucas with about 2½ minutes left in the first half. Izzo told reporters after the game that Lucas, a two-time All-Big Ten selection, probably tore the Achilles tendon in his left foot and will miss the rest of the tournament.
In the Midwest Regional semifinals, the Spartans will play 9-seed Northern Iowa, which upset top-ranked Kansas 69-67 in Oklahoma City on Saturday. No. 2-seed Ohio State, a 75-66 winner over Georgia Tech on Sunday, plays 6-seed Tennessee in the other regional semifinal in St. Louis.
The Spartans weren't the only Big Ten team playing short-handed on Sunday. Purdue, which lost star forward Robbie Hummel to a season-ending knee injury on Feb. 24, defeated Texas A&M 63-61 in overtime in a South Regional second-round game in Spokane (the fourth time in five years the Aggies have lost in the NCAA tourney by two points or less). Senior guard Chris Kramer scored six of the No. 4-seeded Boilermakers' eight points in overtime, including the winning layup with 4.2 seconds to play.
"We might not be as good as the team as we are with Robbie as we are without, but our guys come in and give it our all, and you just have to keep dreaming," Kramer told reporters on Sunday.
Purdue plays No. 1-seeded Duke in the South Regional semifinals in Houston on Friday. The Blue Devils reached the Sweet 16 for the 25th time on Sunday by routing No. 8-seeded California 68-53 in a second-round game in Jacksonville, Fla. No. 3-seeded Baylor plays No. 10-seeded Saint Mary's in the other regional semifinal in Houston.
Syracuse, the No. 1 seed in the West Regional, didn't have any problems reaching the Sweet 16, either. The Orange routed 8-seed Gonzaga 87-65 in the second round on Sunday, after beating No. 16-seeded Vermont by 23 points in the first round on Friday. SU forward Wesley Johnson scored 31 points and grabbed 14 rebounds against the Zags.
The Orange play No. 5-seed Butler in Salt Lake City in Thursday's West Regional semifinals. No. 2-seed Kansas State plays No. 6-seed Xavier in the other game there.
We can only hope the Sweet 16 and Elite Eight are as exciting as the first two rounds. That might be asking for a lot after what we just witnessed:
• For the first time since the NCAA tournament expanded in 1985, three one-bid conferences (the Horizon League, Ivy League and Missouri Valley Conference) had their teams advance to the Sweet 16.
• Thirteen games were decided by three points or fewer and four games were decided in overtime.
• Lower-seeded teams won 16 of the games during the first two rounds, including 11 won by double-digit seeds.
• The South Regional semifinal game between 1-seed Duke and 4-seed Purdue is the only matchup in which the highest possible seeds reached the Sweet 16. And one could argue that even that matchup is a surprise. If they're honest, most will tell you they didn't have the Robbie Hummel-less Boilermakers in the Sweet 16 in their bracket.
• For the first time in four years, none of the four regions has each of its top four seeds in the Sweet 16. That "Bracket of Death" that we all talked about on Selection Sunday -- the treacherous Midwest? Well, that regional is down to a 2-seed, 5-seed, 6-seed and 9-seed.
• The Big Ten sent three teams (Michigan State, Ohio State and Purdue) to the Sweet 16, more than any other conference. Big Ten teams went 7-2 in the first two rounds.
•The Big East, which had eight of its 16 teams playing in the NCAA tournament, has only two teams in the regional semifinals (Syracuse and West Virginia). Big East teams went 6-6 in the first two rounds.
• For the third time in four seasons, only one ACC team (Duke) reached the Sweet 16. Before this current stretch, the conference sent at least two teams to the regional semifinals in each of the previous 27 NCAA tournaments. ACC teams went 5-5 in the first two rounds.
• How's this for parity? Eleven different conferences have teams playing in the regional semifinals, including two teams (Kentucky and Tennessee) from the much-maligned SEC and one team (Washington) from the much-more-maligned Pac-10.
• And for only the third time since 1985, four teams seeded 9th or worse (No. 9 Northern Iowa, No. 10 Saint Mary's, No. 11 Washington and No. 12 Cornell) reached the Sweet 16.
Bottom line: That was one heck of a way to open up the 2010 NCAA tournament.
Enjoy catching your breath over the next few days. Here's hoping we all need more rest after next weekend.
Mark Schlabach covers college football and men's college basketball for ESPN.com. You can contact him at email@example.com.