Las Vegas sportsbooks were hit hard by the Philadelphia Eagles’ 41-33 upset Super Bowl victory over the New England Patriots on Sunday night.

It was a particularly brutal outcome for William Hill sportsbook, where three people made bets of at least $1 million on the Eagles (who closed as a consensus 4.5-point underdog).

USA Today’s A.J. Perez reports that William Hill lost $4,634,782 on those three bets alone. Perez adds that 54% of the bets against the spread were on the Eagles, 75% of the moneyline bets were on the Eagles, and 54% of the over/under bets were on the over (which easily hit at 74 points; most books closed at 49 points for the o/u).

Covers.Com’s Patrick Everson was told by a Treasure Island spokesman that the Super Bowl was a “horrible outcome” and the “props were so disastrous that it ruined the whole day.”

CG Technology also told Everson that they came out on the losing end.

And Everson was told by an MGM Grand spokesman that a bettor had a $3 million bet on the moneyline for the Eagles, which will pay the bettor between $4.5 and $5.4 million.

However, MGM claims that they still came out a small winner on the night, due to a lot of action in-game wagering on the Patriots.

It seems one mystery bettor was responsible for a lot of the damage. The Las Vegas Review Journal’s Todd Dewey reports that the bettor won over $10 million by taking the Eagles on at least $7.4 million in moneyline bets.

ESPN.Com’s Ben Fawkes has an article on the mystery bettor, known as “Bettor X” in the betting community. Bettor X reportedly “spread big bucks across town, all on the Eagles.”

Here’s what it looked like in The Mirage sportsbook when the Eagles won:

About Matt Clapp

Matt is an editor at The Comeback. He attended Colorado State University, wishes he was Saved by the Bell's Zack Morris, and idolizes Larry David. And loves pizza and dogs because obviously.

He can be followed on Twitter at @Matt2Clapp (also @TheBlogfines for Cubs/MLB tweets and @DaBearNecess for Bears/NFL tweets), and can be reached by email at mclapp@thecomeback.com.