Indiana and Eastern Kentucky suffered their first losses over the weekend, leaving just eight teams remaining with unblemished records.
Duke (9-0) Cincinnati (10-0), Syracuse (9-0), Illinois (12-0), Michigan (11-0), New Mexico (11-0), Wyoming (10-0) and Arizona (8-0) are perfect midway through December.
Who will be next to lose?
Three of the eight face tests in rivalry games this week. They are the most likely candidates considering the nature of the those games.
Cincinnati plays crosstown rival Xavier (7-2) on Wednesday. The game produced one of the lasting memories of the 2011-12 season when a the teams brawled with 9.4 seconds remaining in Xavier's victory. Cincinnati will go into this year's game battle tested, having played three tough opponents already in Iowa State, Oregon and Alabama.
New Mexico also plays Wednesday on the road at in-state rival New Mexico State. But the Lobos just beat the Aggies handily on Saturday in Albuquerque in the front end of this annual home-and-home matchup. The truth is this hasn't been much of a rivalry in recent years with the Lobos winning nine of the past 10 in the series. Still, these games are played with a March intensity and funny things sometimes happen with heightened emotions.
Illinois is off to its best start since going 15-0 to open the 2005-06 season. Coach John Groce's doesn't play next until Saturday when it faces Missouri (8-1) in the Braggin Rights game. The Illini have the most difficult test against a Missouri team whose only loss so far came at No. 2 Louisville. The Tigers have a warmup tonight at home against South Carolina State.
While Illinois could easily be the nest undefeated team to fall, it was on the other end of that scenario over the weekend, handing Eastern Kentucky its first loss. The Illini have two good wins on their record having survived matchups with Butler and Gonzaga, but they have appeared vulnerable at times.
Follow Kyle on Twitter @KyleRingo