LSU had been a consensus 6-point favorite over Clemson late last week and was attracting 80-90% of the money at sportsbooks around the nation.
Money on underdog Clemson -- much of it from professional bettors -- started to appear over the weekend and continued throughout game day. The line closed as low as LSU -4 at some sportsbooks.
Multiple bookmakers reported taking bets on Clemson from respected players Monday afternoon, pushing the line down, even though there was more money on LSU overall.
At kickoff, nearly 60% of the point-spread bets that had been placed at Caesars Sportsbook were on LSU.
Online sportsbook PointsBet, which operates primarily in New Jersey, reported that its sharp clients had been "conspicuously quiet" until Monday afternoon, when bets from respected accounts began coming in on Clemson.
Nevada sportsbooks saw a similar increase in Clemson money.
"Sharp money came in at +6 and now the public is starting to weigh in on Clemson also," Jeff Stoneback, director of MGM sportsbook in Nevada, told ESPN on Monday.
With a two-week buildup to the game, bookmakers were raving about the betting interest in the game, and big bets on each team were reported. The sportsbook at The Beau Rivage in Biloxi, Mississippi, took a $400,700 bet on LSU -5, while in Nevada, a bettor took Clemson +5.5 for $220,000 at an MGM sportsbook.
The over/under total on the game also had significant movement Monday. It had been as high as 71.5 at some books but closed at 66.5.