Amid all the blowouts so far administered by the contenders, the upsets restored some crackle — if not the desired outright mayhem — to the bracket after the least eventful opening day of the tournament since 2000, when the higher seeds went 15-1.
They went 14-2 on Thursday, a trend that continued Friday in the first five games — but almost didn’t. Arkansas scored the final 7 points while benefiting from a controversial call in the final seconds to defeat Seton Hall, 77-71, in the South. Trailing by a point with about 20 seconds left, the No. 9 Pirates — who lost in their only national championship game appearance, to Michigan in 1989, after a dubious foul call — set about trying to foul Arkansas in order to regain possession quickly.
Desi Rodriguez did so, pushing Jaylen Barford in the back, causing him to fall. The officials called an immediate foul, and after reviewing the play, ruled a Flagrant-1 foul, which awarded Arkansas two foul shots and possession. Barford made both free throws, and Daryl Macon followed by making one of two to seal the victory.
J. D. Collins, the N.C.A.A.’s national coordinator of men’s basketball officiating, supported the officials’ decision afterward in an interview on TNT, saying that any time a player “puts two hands in the back and doesn’t make any attempt to play the ball or the player in front of him,” it’s a flagrant-1 foul.
Barford said he was surprised that he was shoved, though Seton Hall Coach Kevin Willard disputed Rodriguez’s intent.
“If you’ve been around the game long enough, you’ve got to know time, score — you’ve got to know what’s going on,” Willard said, adding, “But they reffed a good game all night. So I can’t really complain about whether I agree or not. I’m always going to disagree with it. That’s what coaches do.”
Coaches also do not lament what they do not have, and Oregon pressed on Friday in its second game without the shot-blocking menace Chris Boucher, who tore a knee ligament last weekend in the Pacific-12 tournament semifinals. Sitting on the bench, Boucher watched his teammates throttle No. 14 Iona, 93-77, in a Midwest Region game that the Ducks once led by 27 points.
North Carolina, the top seed in the South, dwarfed that margin in clobbering No. 16 Texas Southern, 103-64, while No. 2 Louisville distanced itself in the second half from pesky Jacksonville State, winning by 78-65 in the Midwest.
No. 3 Baylor exploited its physical dominance against undersized No. 14 New Mexico State in the second half, cruising to a 91-73 victory in the East Region.
U.C.L.A., the third seed in the South, never had too much to worry about with Kent State, whom it beat, 97-80. But late in the first half, the Bruins held their breath when the freshman sensation Lonzo Ball landed hard on his right hip after leaping for a pass. Ball was knocked down, but not out. He finished the game with 15 points and 3 assists.
Earlier in the evening, after trailing, 19-8, midway through the first half to No. 8 Miami, Michigan State woke up. And oh, did it ever: The Spartans outscored the Hurricanes, 70-39, to win by 20 in Tulsa, Okla.
But no team has been hotter than the Spartans’ rivals from Ann Arbor, Mich. The No. 7 Wolverines edged No. 10 Oklahoma State, 92-91, in the Midwest Region, on the strength of that great equalizer: the 3-point shot.
Outscored in the paint by 30 points, and outrebounded by 19, Michigan hit 16 of 29 shots from behind the arc — including 11, on 15 attempts, in the second half. “That’s hard to do in a gym by yourself,” Oklahoma State Coach Brad Underwood said.
In its play-in game on Wednesday against Providence, U.S.C. had to erase a 15-point halftime deficit just to join the main field. Down by 12 against S.M.U. on Friday, the Trojans grabbed their first lead with about two minutes left, then scored the game’s final points on an Elijah Stewart 3-pointer with 36 seconds left.
After each team missed the first free throw of a one-and-one, S.M.U. played for a final shot, an errant off-balance leaner by Shake Milton. Tim Jankovich, the S.M.U. coach, mentioned the introductory sequence of “Wide World of Sports” when describing his emotions afterward — the agony of defeat.
“I can certainly relate to that show right now,” Jankovich said.
The other U.S.C., South Carolina, pulled away late from No. 10 Marquette to win, 93-73, in Greenville, S.C. The Gamecocks, led by a monster performance by Sindarius Thornwell (29 points and 11 rebounds), won their first N.C.A.A. tournament game since 1973.
No. 7 Dayton and No. 10 Wichita State engaged in what seemed like a mud wrestling masquerading as basketball. It was tough to penetrate, tough to score, and, at times, tough to watch. But the Shockers outmuscled the Flyers (who shot 31 percent), 64-58.
Rhode Island might be one of the few teams capable of matching the Shockers’ tough defense. After the game, Rams forward Hassan Martin summed up what it feels like to give Rhode Island its first N.C.A.A. tournament win since 1998.
“Honestly,” Martin said, “it feels like I’m dreaming.”