But Matsuyama gave himself a great chance at birdie and a bronze medal, landing within 10 foot of the pin.
Casey was unable to match Matsuyama’s efforts, leaving him a difficult two-putt to stay in the hunt.
But Schauffele showed nerves of steel to float his approach shot to within a few feet of the flag for par and ultimately the gold medal.
Matsuyama missed his birdie chance though while Casey did enough to stay at 15-under.
It meant that all seven players on 15-under would go on to play in a play-off for the bronze medal.
Casey and Matsuyama were joined by McIlroy, Collin Morikawa, Sebastian Munoz, Pan Cheng-Tsung and Mito Pereira.