According to ESPN.com's David Purdum, a bettor at the William Hill U.S. sportsbook turned an $85,000 bet into a $1.19 million payout. Woods was a 14-1 favorite to win when the bettor placed the wager Tuesday.
"It's great to see Tiger back," said Nick Bogdanovich, William Hill's director of trading. "It's a painful day for William Hill—our biggest loss ever—but a great day for golf."
Purdum noted the SuperBook at Westgate Las Vegas had a "high five-figure net loss" on bets tied to the Masters outcome.
Woods shot two under in the final round to finish at 13 under for the tournament. He edged out Dustin Johnson, Brooks Koepka and Xander Schauffele by one shot.
With five Masters titles, Woods is now alone in second place, one green jacket behind Jack Nicklaus. Woods is three major titles behind Nicklaus for the all-time mark as well.
The 2019 PGA Championship begins May 16 at Bethpage Black in Farmingdale, New York. Ahead of the tournament, sportsbooks will likely take more precautions to ensure they don't end up in the red should Woods triumph again.