Teams on Upset Alert in Day 5 of 2018 NCAA Tournament

Three teams felt the bite of the underdog Thursday in the first day of widespread action in the men's NCAA tournament.

No. 13 Buffalo pulled off the biggest upset of the day, and it wasn't close. The Bulls blew out a listless Arizona team by 21 points, 89-68. 

Elsewhere in the South Regional, another upset was less impactful from a seeding standpoint but delivered a larger dose of March Madness drama. Donte Ingram hit a three-pointer with 0.3 seconds left to lift No. 11 Loyola Chicago past No. 6 Miami.

Finally, No. 9 Alabama's 86-83 win over No. 8 Virginia Tech was technically an upset, and it was a great game, but it wasn't what you'd call a shocker.

Where could the drama lie Saturday? Thursday's winners are queued up for the Round of 32. Here are the teams that look vulnerable to the underdog's bite when the action begins.

Only significant favorites and underdogs are considered. We're assessing the status using odds from OddsShark, as opposed to strictly their seeding. Statistics courtesy of ESPN.com unless otherwise noted.

Villanova Wildcats

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Collin Sexton

No. 1 Villanova vs. No. 9 Alabama (East)

Odds: Villanova -700, Alabama +530

I'm not going to pretend like I watched Alabama all season or that I expected the Crimson Tide to knock off a Virginia Tech team that sported wins over Virginia, Duke and North Carolina.

But I caught up quickly, and the first lesson was the easiest: Collin Sexton is the freaking truth.

The Crimson Tide point guard finished second in the SEC with 19.2 points per game and dropped 25 on the Hokies, along with six assists.

Plenty of NBA scouts will watch this game with interest. NBADraft.net has Sexton as a lottery pick, with his Villanova counterpart, Jalen Brunson, going in the second round. That will be a captivating matchup.

Brunson and the Wildcats run a tight offensive ship, scoring 87 points per game and ranking tops overall in the KenPom offensive efficiency rankings. However, even though Alabama is all the way down at 97th in those offensive ratings, the Tide outrank Villanova defensively, clocking in at 18th to the Wildcats' 26th.

Villanova is favored for a reason, but if Alabama gets a complete effort on defense and another offensive gem from Sexton, it could find itself in the Sweet 16.

Duke Blue Devils

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Marvin Bagley III

No. 2 Duke vs. No. 7 Rhode Island (Midwest)

Odds: Duke -500, Rhode Island +450

A perfect game from Rhode Island can get it done.

The Blue Devils were on cruise control in their first game, overwhelming Iona by 22. Duke has talent everywhere, as always, and Marvin Bagley III is on another level. No one can stop the 6'11" forward; certainly not on Iona, which surrendered 22 points and seven boards to the superfrosh.

It could be the same story for Rhode Island. The Rams don't have a regular rotation player taller than 6'8". Their second- and third-leading rebounders, Stanford Robinson and E.C. Matthews, respectively, are both guards and stand 6'4" and 6'5".

That is a huge problem against Duke, which sits third in the nation with 41.8 rebounds per game. Alongside Bagley, the 6'10" Wendell Carter Jr. and the overlooked Javin DeLaurier, also 6'10", are Windex on the glass.

The Rams will concede the paint to Duke and will need to put their energy into perimeter defense. They were effective in limiting Oklahoma sensation Trae Young in their first contest. Duke still relies on the three ball for a fair amount of its offense, and if those shots are contested and aren't falling, the team could start to press.

Another potential storyline: Carter revealed after the Iona win that he is playing with a sore Achilles tendon. That could soften Duke's frontcourt advantage a bit.

The Rams are good shooters too (35 percent from deep as a team this season to Duke's 38 percent) and play an uptempo style behind guards Jared Terrell, Fatts Russell and Matthews. If they make it a team effort and make Duke uncomfortable, they may just have a shot.

Kentucky Wildcats

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Kevin Knox

No. 5 Kentucky vs. No. 13 Buffalo (South)

Odds: Kentucky -260, Buffalo +230

Not a lot of teams win 25 games and still face accusations of having a down year. But that's where Kentucky was this season. Squeaking by a frisky but undersized Davidson squad—while going 0-of-6 from beyond the arc—gave more fuel to the notion.

Now the Wildcats face Buffalo after the Bulls' surprising win over Arizona. They used superior quickness on both ends to run the Wildcats out of the building.

What's more, the Bulls' relentless pressure defense gave Arizona's guards fits, and there's no reason they can't do the same against Kentucky's backcourt. Kentucky has more speed than Arizona, so the Bulls' advantage won't be so pronounced. At the same time, the Wildcats committed 12.9 turnovers per contest this season (177th in the nation).

If the Bulls can harness the energy from Thursday's win and avoid a hangover, they can topple their second consecutive pack of Wildcats.

Tennessee Volunteers

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Admiral Schofield

No. 3 Tennessee vs. No. 11 Loyola Chicago (South)

Odds: Tennessee -235, Loyola Chicago +230

No two ways about it: This is a close matchup.

Tennessee flies under the radar in college basketball. The SEC is not the glamor conference it is during football season, and the Vols' 73-47 pulverization of Wright State Thursday was their first tournament win in four years.

There was inconsistency inside this campaign as well, with a shaky 9-4 start giving way to a 25-8 season. 

The key to their success is depth and defense. They're fifth in the KenPom defensive rankings and have seven players posting at least 20 minutes per game, paced by forwards Grant Williams and Admiral Schofield.

Loyola Chicago is flying high after its big win against Miami. What does Sister Jean have in her bag of tricks for the Vols? Turns out the Ramblers are similar to their power-conference foes.

Riding an 11-game win streak, Loyola Chicago got it done largely with defense (27th in the KenPom rankings). And if you like Tennessee's depth, you'll enjoy Loyola Chicago, which plays seven guys for at least 19 minutes per game.

The Ramblers also have the size to prevent outright mismatches; versatile 6'9" center Cameron Krutwig is a linchpin there. They have great three-point shooting: 39.7 percent (22nd). As it happens, Tennessee is 21st nationally in defending the three.

You get the idea. This will come down to matchups and game plans, a struggle to shade the other guy just enough toward something he doesn't want to do. Tennessee won't be able to force the Ramblers off the floor.

Whoever wins, it will take a complete effort.