Wallace, who won in India and Germany earlier in the season, had also birdied five of his last six holes in regulation play to force his way into the playoff and the 28 year old from London will now move just outside the top 50 in the world, his highest ever ranking.
Wallace was clearly delighted with his effort and acknowledges that while not qualifying automatically for the European Ryder Cup team he has done as much as he can to keep his name in the mind of captain Thomas Bjorn.
“I’m so happy, ecstatic. Hard work again, pays off,” he said. “Determination, grit, everything that I believe takes to win a tournament and I said it yesterday: You need to putt well to win, and I've found a way to get it done where I put myself under pressure in practise, and then it comes up trumps on a Sunday. Ball-striking can take you there, and then putting takes over.
"I think I have given Thomas (Bjørn) something to think about. That was the plan. I put myself under pressure, the last couple of days, as well, by saying I want to give him a headache. I've stepped up to the mark and I've shown him exactly what I'm about.
“If he doesn't pick me, then that's absolutely fine. That's absolutely fine. But I've shown him everything that I'm about, and if he doesn't, then so be it, but if he does, he knows he's going to get exactly that in his team.”
While Wallace’s Ryder Cup’s fate is still in doubt, local golfer Thorbjorn Olesen secured the last spot of the automatic qualifiers narrowly holding off a strong late challenge from Matthew Fitzpatrick whose last round of 66 to finish 7th left him just short.
Olesen finished 20th this week and joins Tommy Fleetwood, Tyrell Hatton, Rory McIlroy, Francesco Molinari, Alex Noren, Jon Rahm and Justin Rose, as automatic team members with four more to be named by Bjorn on Wednesday.
Bjorn is aware of the difficult task he faces over the next few days and the emotions he is going to create, both disappointment and elation.
“It’s a great position to be in," said the Dane. "A lot of guys playing well. Yeah, we're in a situation where we're going to make somebody really happy and we're going to let somebody down, and that's fortunate and unfortunate in the same breath, and that's the way it is.
"As a captain, you sometimes probably hope when you have four picks, there's going to be four and that's not the case this time. There's a bit of thinking and a bit of stuff to do. "
Nick Cullen and Josh Geary finished as the leading Australasians but they were well down the field in a share of 49th place, Marcus Fraser and Matthew Millar were 56th, Brett Rumford 65th after starting the week so well on Thursday and Jason Scrivener 69th.
RULES: BALL MOVED BY WIND
Want video tips delivered straight to your inbox? Subscribe to iseekgolf.com newsletters.