The American closed with a final-round 70 to claim a top-20 finish, but not before making a memorable birdie on the second hole in the unlikeliest of circumstances.
McCarthy's tee shot on the par-four second went well off target and into a group of patrons watching the action, connecting with one of the spectators before going straight into the cupholder of the unlucky fan's portable folding chair.
"Long-range hole-in-one," McCarthy joked while surveying his unlucky lie. "That's a hole-in-one."
McCarthy was allowed to take a straight drop without losing any strokes, and was able to hit his second shot to within 35 feet of the hole, sinking the long-range effort to record one of the more unusual birdies you're likely to see.
The 29-year-old ultimately finished seven shots behind champion Will Zalatoris in an eight-way tie for 20th place after a few disappointing bogeys down the stretch.
McCarthy has five top-10 finishes to his name this season, including a top-five finish at Jack Nicklaus' Memorial Tournament and a top-six finish at the John Deere Classic.