It is one of the biggest wins of the American's career, and the triumph at Austin Country Club is also the first time Horschel has won a WGC event.

Horschel faced Frenchman Perez in the semi-finals this morning and the pair were level after nine holes, but Horschel made fewer errors on the back nine to earn a 3-and-2 win.

Perez made bodies on 10, 11 and 14, giving Horschel a three-shot lead, and despite winning the 15th Perez lost the match when he was unable to match Horschel's birdie on the par-five 16th.

Scheffler beat Olympic bronze medallist Matt Kuchar by one hole in the other semi-final, an all-American affair, with a birdie on the par-three 17th proving decisive.

And Scheffler started well when it came to the final, making a birdie on the second hole to Horschel's bogey, but that would turn out to be the only hole Scheffler won in the match.

Horschel leveled things up on the fifth and had a two-hole lead by the end of the front nine, which is how it stayed until the conclusion on the 17th hole.

There was also a 2-and-1 victory in the third-place playoff, with Kuchar emerging victorious.

Kuchar now has 34 career wins at the WGC-Match Play, second on the all-time leaderboard.

Horschel's win means all of the four WGC titles are currently held by Americans.

Collin Morikawa won the WGC-Championship in Florida last month, where Horschel finished in a tie for second.