The American won by a single shot from Bernhard Langer at Sunningdale.
Marco Dawson won his second title of the year at the Senior Open Championship at Sunningdale.
The American shot a final round 64 to finish one shot ahead of defending champion Bernhard Langer.
Colin Montgomerie was three shots back from Dawson after 72 holes, with the former Ryder Cup captain making consecutive bogeys after the turn.
"I was nervous coming down the stretch," said Dawson afterwards.
"These guys are playing well and making birdies left and right. I thought I've got to do something, so I said, you know what, let's just make the swing and see what happens.
"Quit playing conservative, just make the swing."
Dawson, 51, holed a crucial birdie putt on the 18th to take his first Senior major.
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He made two eagles during his final round, on the par 4 9th and the par 5 14th, before closing with three straight pars and a birdie.
Langer made par or better on every hole, claiming six birdies in total, but it wasn't enough to stop Dawson from winning in Berkshire.
The win also means qualification for The Open at Royal Troon next year.
Dawson said: "That [qualification] will be great. I love coming over here. This is only my second time here and I love the way it's played differently here.
"There's so many more options off the tee and on the fairways and on the greens."
Marco Dawson 65 67 68 65 -16 264
Bernhard Langer 65 68 68 64 -15 265
Colin Montgomerie 67 67 66 67 -13 267
Miguel Angel Jimenez 65 69 68 67 -11 269
Woody Austin 69 67 70 66 -8 272
Fred Couples 68 66 69 69 -8 272
Jeff Maggert 71 67 66 69 -7 273
Philip Walton 71 67 65 70 -7 273
Esteban Toledo 73 68 68 65 -6 274
Jeff Sluman 65 69 70 70 -6 274
Peter Fowler 69 65 68 72 -6 274
Arnold Palmer Invitational Field 2025
Arnold Palmer Invitational Prize Money Payout 2025
