Some NCAA tournaments start with an emphatic thud, marked by chalky brackets and blowout scores.

This is not one of those NCAA tournaments. Thursday opened with No. 4 seed Virginia falling early thanks in part to one of the more bizarre decisions in tournament history. No. 2 Arizona did Virginia one better in a stunning loss to Princeton that obliterated brackets and officially marked a trend.

No. 1 seed Alabama, meanwhile, cruised as expected, but did so without a single point from All-American Brandon Miller. Fellow No. 1 seed Houston did not look like a national championship contender. And that talk about Duke being under-seeded? So far, it sounds right.

Here's what stood out on the first day of NCAA tournament play.

Princeton extends 15-seed trend: How far will it go?

No. 15 seeds winning in the NCAA tournament is now a thing.

Prior to 2021, eight No. 15 seeds advanced past the first round in the 35 seasons since the NCAA tournament expanded to 64 teams in 1985. As of Thursday, it's now happened three years in a row.

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Welcome to the club, Princeton. The Ivy League champions kept things close all game against No. 2 seed Arizona on Thursday, then took a 56-55 lead with 2:03 remaining. They never trailed again. The Tigers held on for a 59-55 win as they repeatedly frustrated late Arizona scoring efforts to pull off the upset of the tournament — so far, at least. In doing so, they followed in the footsteps of 2021 Oral Roberts and 2022 Saint Peter's.

Oral Roberts beat No. 2 Ohio State in the opening round of the 2021 NCAA tournament. The win sparked a trip to the Sweet 16 for the Golden Eagles after a second-round win over Florida. A two-point loss to Arkansas ended their run short of the Elite Eight.

Saint Peter's one-upped the Golden Eagles last year after a stunning opening-round win over No. 2 Kentucky. From there, the Peacocks beat Murray State and Purdue en route to an Elite Eight loss to eventual national finalist North Carolina.

How far can Princeton extend its Cinderella run? No. 7 seed Missouri awaits on Saturday.

Arizona, meanwhile, is left to regroup. As is former Wildcat Rob Gronkowski.

Is Virginia's style flawed for NCAA tournament play?

Virginia secured its first-ever NCAA championship in 2019. Outside of that pinnacle achievement, it's been a rough few years for Tony Bennett and the Cavaliers in tournament play.

Thursday brought more pain to Charlottesville as No. 13 Furman upended No. 4 Virginia in stunning fashion. An errant pass by fifth-year senior Kihei Clark set up Furman's JP Pegues to sink the Cavs with a 3-point dagger in the game's final seconds.

Pegues' shot secured a 68-67 Paladins win and marked Virginia's third first-round exit in its last four tournament appearances. All three of those exits arrived as massive NCAA tournament upsets.

The 2018 loss as a No. 1 seed to No. 16 seed UMBC remains the biggest seeding upset in NCAA history. Thursday's loss to Furman rivaled 2021's to Ohio in another first-round 13-4 matchup.

Bennett's teams play and win by unleashing a swarming defense next to a grind-it-out offense that runs deep into the shot clock. It's a style designed to frustrate and befuddle opponents. It also leaves the Cavaliers open to upsets in games where neither team breaks away.

Brandon Miller's bad day

Alabama looked fine in beating Texas A&M-Corpus Christi on Thursday.

Brandon Miller did not. The Alabama All-American who entered NCAA play amid a torrent of controversy was held scoreless in the Crimson Tide's 96-75 win. Miller entered halftime with five rebounds, two assists and zero points. After picking up his second and third fouls early in the second half, his day was done.

Miller finished the day with zero points, five rebounds and three assists in 18 minutes while shooting 0 for 5 from the field and 0 for 3 from 3-point distance. He entered Thursday averaging 19.6 points 8.3 rebounds and 2.1 assists per game. He'd scored in double figures in all but one of Alabama's previous 34 games. He's the best player on the tournament's overall No. 1 seed and a projected top-three pick in the NBA draft.

Alabama head coach Nate Oats told reporters after the game that Miller was nursing a groin injury sustained last week and that they "were trying to play him limited minutes."

That Alabama beat a No. 16 seed by 20-plus points isn't significant. This is what No. 1 seeds are expected to do. Miller's performance and potential injury issue is.

Police say that Miller delivered a gun to the scene of a fatal January shooting that resulted in a capital murder charge against now-dismissed teammate Darius Miles. Miller's not facing charges. But his alleged involvement in the incident has cast a pall over Alabama as it seeks its first-ever national championship.

The impact on the basketball program is visible. Miller entered Birmingham's Legacy Arena on Wednesday flanked by an armed bodyguard.

Oats told reporters that security is on the scene after threats directed toward Miller in the aftermath of January's shooting. Is the ordeal catching up with Miller on the court with the basketball spotlight intensifying? How Miller performs in Saturday's second-round game against Maryland will be telling.

Houston is injured, vulnerable

No. 1 seed Houston survived on Thursday but didn't inspire confidence in a win over No. 16 Northern Kentucky. The Cougars went into halftime with a 30-27 lead, then came out of halftime without All-American Marcus Sasser.

The junior guard aggravated a groin injury before halftime and didn't return in the second half. It wasn't because Houston didn't need him. Northern Kentucky tied the game at 36-36 as Houston repeatedly turned the ball over. An 11-2 run capped by a pair of Emanuel Sharp 3-pointers eventually gave Houston some breathing room in a 47-38 lead. The Cougars escaped with a 63-52 win.

Coach Kelvin Sampson revealed after the game that guard Jamal Shead played through a hyperextended knee. Shead finished with 13 points and six assists. While he didn't have a specific update about Sasser's injury, Sampson did say he was "very concerned."

The decision to play at all, Sampson said, was left completely up to Sasser.

This was not the team supporters expected when Houston opened as the betting favorite to win the national title. The Cougars turned the ball over 17 times while allowing Northern Kentucky to corral 18 offensive rebounds. A 5-of-34 (14.7%) NKU shooting effort from 3-point distance saved the Cougars from disaster.

Houston very much looks vulnerable. It will be on Saturday against Auburn if Sasser can't play.

Duke flexes on heels of strong ACC finish

After a strong conference finish that included an ACC tournament championship, Duke landed the No. 5 seed in the East region. Some thought that was too low. Based on Thursday's effort against Oral Roberts, it might have been.

First-round 12-5 matchups make for popular bracket upset picks. The Blue Devils put any thoughts of an upset to bed early in a 74-51 blowout of the Golden Eagles.

This Oral Roberts team was no pushover. It won 30 games during the regular season and featured two-time Summit League Player of the Year Max Abmas. If that name rings a bell, it's because Abmas led the Golden Eagles to the Sweet 16 in 2021 from the 15-seed line.

But there's no Cinderella run for Abmas in 2023. Duke's burgeoning defense limited Abmas (22.4 points per game) to 12 points on 4 of 15 shooting from the field. He was ORU's leading scorer as the Golden Eagles shot 30.2% from the field as a team. Duke's defense anchored by ACC All-Defensive Team center Dereck Lively is for real.

Duke's offense, meanwhile, got the job done despite a subpar outing from All-ACC freshman Kyle Filipowski, who finished well below his season scoring average with six points alongside nine rebounds. Instead, junior guard Jeremy Roach led the offense with 23 points on 9-of-17 shooting. Freshman Dariq Whitehead added 13 points on 5-of-7 shooting off the bench.

Duke has a lot of young talent, including four freshman starters who have gelled at the right time. One game in, it looks like a legitimate NCAA tournament threat.