Williamson fell awkwardly 36 seconds into the game, limped back to the locker room and was ruled out for the remainder of the contest.
Duke remains the consensus national title favorite in Las Vegas, but Caesars Palace lengthened the Blue Devils' odds from +200 to +250 after the Williamson injury.
Duke has attracted by far the most betting support. More than twice as much money has been bet on the Blue Devils to win the national title as has been bet on any other team at Caesars Palace and William Hill sportsbooks. Twenty percent of the money that has been bet on William Hill's odds to win the national championship was on Duke as of Wednesday.
Gonzaga's odds improved from +700 to +500, and Virginia and Kentucky each saw their odds shorten from +800 to +700 at Caesars Palace.
Oddsmakers estimated Williamson's value to the point spread was from four to five points depending on the opponent.
Zion will not return vs. UNC after knee injury
Zion Williamson hurts his knee less than a minute into the game and will not return against North Carolina.