Just under three weeks after being denied a captain's pick for the Presidents Cup, Spaun birdied four of his last five holes for a five-under 67 that brought him to 17 under on the week at Wentworth and left him two shots clear of a quartet of players that included world number two Rory McIlroy and former Masters winner Adam Scott.
Spaun, who started the final round one shot off the lead, said afterward that the snub fuelled his run to the title.
"I played with a huge chip on my shoulder. I definitely had something to prove this week," Spaun told reporters. "But everything happens for a reason. I'm so delighted to be here and just to even play this event."
Snedeker used his six captain's picks on Justin Thomas, Xander Schauffele, Patrick Cantlay and Presidents Cup rookies Chris Gotterup, Jacob Bridgeman and Jackson Koivun.
Spaun said he did not message Snedeker after his win, adding that the two haven't spoken. Instead, Spaun let his clubs do the talking.
"Being left off the Presidents Cup team a couple weeks ago was very disappointing, and you know, I wanted to prove that I deserve to be on that team," said Spaun. "I took care of my business this week. So all the best to the team next week at Medinah and I'll be watching."
The 2026 edition of the Presidents Cup, a biennial event that pits a US team against a lineup of international players from outside Europe, will be held at Medinah Country Club's Course No. 3 in Chicago.
The US are 13-1-1 in the Ryder Cup-style competition, with their only loss coming at Royal Melbourne Golf Club in Australia in 1998.