Fox earns €220,315 ($442,525) on his return to England since winning the Open Championship in July.
Arnold Palmer and two-time winner Billy Horschel are the only other Americans to win the DP World Tour event.
“It means so much. You know, I’ve kind of blossomed into this player I never thought I could be, and to take my game across the world, and more specifically here in England, a place that’s dear to my family’s heart, we vacation here quite a bit,” Spaun said.
“The stars kind of aligned this week for me to come out on top, and I’m just grateful to have the opportunity and play and play well and give myself a chance and came out with a W.”
Daniel Hillier finished in a share of 36th at nine-under with Kazuma Kobori in 56th at five-under. Hillier remains in 12th on the season rankings, which would earn a PGA Tour card as it stands.
Fox now heads back to the US for the Presidents Cup which starts at Medinah Country Club in Illinois.