The ranks of the unbeaten shrunk from six to five this past weekend — with arguably the least likely loser suffering its first defeat of the campaign.

Michigan, which was beating teams by an average of more than 30 points entering last week, played with fire on the road at Penn State with a two-point win on Tuesday then gave up 54 second-half points to Wisconsin on Saturday en route to a 91-88 loss.

Now just five unbeatens remain: Arizona, Iowa State, Vanderbilt, Nebraska and Miami (Ohio).

Which will be the next to lose? Which will be the last remaining unbeaten? Which teams have staying power?

Let’s take a look at how each got here and the biggest upcoming tests.

Editor’s note: This is an updated version of a story that first published on Dec. 29, 2025.

Record: 16-0
Jan. 5 AP Top 25 ranking: 1

How they got here: Behind an exceptional debut from freshman Koa Peat (30 points), Arizona opened the season with a win over reigning champion Florida in Las Vegas and has racked up more quality wins since then. The Wildcats hold victories over UConn, Alabama, UCLA, Auburn and San Diego State, with only one of those coming on their home floor in Tucson. Their defeat of UConn in Storrs was one of the most impressive wins we’ll see from any team this season. And they cruised to blowout wins over Utah, Kansas State and TCU to start Big 12 play.

Why they’re unbeaten: Coach Tommy Lloyd has a tougher, more physical team than usual that could deliver the program its first Final Four since 2001. The roster is extremely well-balanced. Peat was sensational early, but his classmate Brayden Burries has been the offensive focal point of late. Jaden Bradley looks like one of the best point guards in the country as a senior, and the center duo of Motiejus Krivas and Tobe Awaka has few peers. Arizona is incredibly dominant inside but shoots better than 37% from 3. The Wildcats are also ranked in the top five nationally in defensive efficiency.

Biggest upcoming test: Jan. 26 at BYU

Arizona’s Big 12 schedule is backloaded; the Wildcats won’t face Kansas, Texas Tech, Houston, Baylor or Iowa State until February. A Jan. 17 trip to UCF could be tricky, but Arizona should win that one, too. So we’ll circle the Wildcats’ trip to Provo for a date with potential No. 1 NBA draft pick AJ Dybantsa and coach Kevin Young’s top-10 Cougars.

Record: 16-0
Jan. 5 AP Top 25 ranking: 3

How they got here: After losing scorers Keshon Gilbert and Curtis Jones from last season’s roster, there were questions about whether coach TJ Otzelberger could keep the momentum rolling for another campaign. But it was Iowa State’s trip to Las Vegas that opened eyes. The Cyclones beat St. John’s in their Players Era Festival opener, then blew out Creighton and Syracuse. And if there were any remaining doubts, those were answered with a stunning 81-58 win over then-No. 1 Purdue — in West Lafayette. They backed that up with a victory over rival Iowa less than a week later then opened Big 12 play with a trio of double-digit wins over West Virginia, Baylor and Oklahoma State.

Why they’re unbeaten: As is typically the case with an Otzelberger-coached team, the key revolves around the defensive end. Iowa State is again one of the country’s elite defenses, forcing turnovers at a higher rate than all but two teams. Tamin Lipsey is known as a top-notch defender, but freshman Killyan Toure has provided another high-level on-ball defensive player. Joshua Jefferson has taken the next step in his development and become an All-American-caliber player, and Milan Momcilovic has been the best shooter in the country so far this season. As a team, Iowa State shoots nearly 41% from 3, ranking No. 3 nationally.

Biggest upcoming test: Jan. 13 at Kansas

Despite Kansas’ recent struggles, a trip to Allen Fieldhouse always poses problems for visiting teams — especially with Darryn Peterson back and seemingly healthy enough to play 30-plus minutes. Iowa State’s Big 12 schedule is also backloaded, with a six-game stretch in February and March including matchups against Kansas, Houston, BYU, Texas Tech and Arizona.

Record: 16-0
Jan. 5 AP Top 25 ranking: 11

How they got here: Vanderbilt’s win over Alabama last Wednesday was its biggest victory of the season, even if it has since lost some luster following the Tide’s home loss to Texas. But the Commodores have also dominated a slew of very solid opponents with a 12-point win over UCF, a 15-point win over VCU, a 25-point win over Saint Mary’s, a 19-point win over SMU, an overtime road win at Memphis and a 31-point blowout of Wake Forest in Winston-Salem. Vandy ranks in the top 10 across nearly every metric, both from a résumé and efficiency standpoint.

Why they’re unbeaten: Coach Mark Byington has an experienced, explosive unit. The Commodores are one of only six teams to rank in the top 12 in both offensive and defensive rating at KenPom, and both ends of the court are headlined by the backcourt of Tyler Tanner and Duke Miles. Tanner is arguably the most underrated point guard in the country, while Miles has rediscovered his high-level scoring ability from two seasons ago at High Point. Both are also exceptionally disruptive defensively, ranking in the top 25 nationally in steals rate. Tyler Nickel has already made 8 3-pointers in a game twice this season. And Devin McGlockton is the ultimate glue guy.

Biggest upcoming test: Saturday vs. Florida

Vandy and Florida look like the best teams in the SEC, and this weekend will be the only time the two face off. The backcourt battle will be key, given the way Tanner and Miles have been playing. Boogie Fland had his best game as a Gator over the weekend, but he and Xaivian Lee haven’t quite found consistency. The key to this matchup is likely whether Vandy can match Florida’s size up front.

Record: 16-0
Jan. 5 AP Top 25 ranking: 10

How they got here: Nebraska actually holds the nation’s longest active winning streak, dating to last season’s four-game run to win the College Basketball Crown. The Cornhuskers had some early notable wins over Oklahoma, New Mexico and Kansas State on neutral courts but really began to make waves when they ran off a 21-point win over Creighton, a 30-point win over Wisconsin and a road win at Illinois in a one-week span. They then erased remaining doubts by beating Michigan State at home before going on the road to beat Ohio State and Indiana.

Why they’re unbeaten: The Cornhuskers take care of the ball, make 3s and are experienced — it’s a recipe that works. Even back in his days at the helm of Iowa State, Fred Hoiberg typically had one of the more prolific 3-point shooting teams in the country. That has been taken to a new level this season, with Nebraska attempting more than 50% of its shots from beyond the arc. Four players are making at least one 3 per game; three are shooting 38% or better from 3. The return of all-conference forward Rienk Mast, who sat out last season because of a knee injury, has been huge. And Pryce Sandfort is enjoying a breakout season after transferring from Iowa last spring.

Biggest upcoming test: Jan. 27 at Michigan

Nebraska was able to navigate a difficult three-game stretch to open 2026, which should provide some optimism it will be able to manage its next four games before the showdown in Ann Arbor. The Cornhuskers will have trouble with Michigan’s size, but their ability to generate open shots — particularly from the perimeter — should keep the contest close.

Record: 17-0
Jan. 5 AP Top 25 ranking: Unranked (30th in votes)

How they got here: It helps that the RedHawks have the No. 364 strength of schedule (out of 365 teams) in the country, according to average opponent NET rank. Of their first 13 wins, 12 came against teams ranked in the 200s or 300s at KenPom. But winning at Wright State by seven is a legitimately solid victory — then they came out in MAC play with notable win after notable win. They won at Bowling Green, beat preseason favorite Akron at home and nabbed another victory at perennial contender Toledo. It’s also worth noting that coach Travis Steele’s team has been handling most of its opponents with relative ease, ranking in the top 45 nationally in scoring margin.

Why they’re unbeaten: Even considering the caliber of opposition, Miami has been performing on the offensive end at an extremely high level. The RedHawks have scored at least 1.13 points per possession in all but one game this season and rank No. 6 in the country in offensive rating, according to CBB Analytics. They’re averaging nearly 93 points, rank first nationally in field goal percentage and are top five in 3-point percentage. Steele has them humming at that end of the court — nine different players have already scored at least 15 points in a game this season, with six making double-digit 3s total this season.

Biggest upcoming test: Jan. 20 at Kent State

Arguably the two toughest tests of Miami’s MAC season are out of the way — at Bowling Green and vs. Akron — and the RedHawks are projected to be favored in every game the rest of the season. But road trips in league play are always challenging, and the conference is filled with potential losses. One of those is Kent State, which has lost only one home game this season. The Golden Flashes have a veteran coach in Rob Senderoff, they’re experienced and they play fast.