Adam Scott blew his chance to defend the US Masters as world number one as Matt Every claimed his first PGA Tour title in a dramatic climax to the Arnold Palmer Invitational on Sunday.
Scott was seven shots clear of the field after 36 holes at Bay Hill and took a three-shot lead into the final round, but that advantage was wiped out by the time he reached the turn.
The world number two collapsed to a closing 76 to finish 11 under par - he was 10 under after a course record-equalling 62 on Thursday - two shots behind Every, who shot a final round of 70.
Scott's playing partner Keegan Bradley had looked out of contention after dropping three shots in the first three holes and carding further bogeys on the 10th and 11th, but birdied the 12th, 16th and 17th and narrowly missed from 30ft for another on the last to force a play-off.
A tearful Every, who grew up nearby and used to attend the tournament as a spectator, said: "It's really cool. I have had a lot of looks (at wins) and I kept telling myself maybe it's going to come somewhere special. I still can't believe I won.
"It's hard, it's tough man. You just never know if it's going to happen. You get there (in contention) so many times and it's nice to get it done."
Scott had bogeyed the first after twice finding sand, while it was a hooked drive into the water on the third which cost him another bogey.
The 33-year-old steadied the ship with a chip to four feet to set up a birdie on the par-five fourth, but then bogeyed the seventh after his tee shot plugged in a greenside bunker.
Scott had held the outright lead since the early stages of his opening round on Thursday, but that was no longer the case when Every recovered from a bogey on the eighth with birdies at the ninth, 10th and 12th to take the lead.
Another birdie on the 13th took Every two ahead and the 30-year-old soon found himself three clear of the pack when Scott bogeyed the 14th. Scott's tee shot came up well short of the green but he elected to putt through the fringe, running his birdie attempt seven feet past the hole and missing the return.
A massive swing in momentum looked to be on the cards on the 16th when Every pushed his tee shot into the trees and failed to find the fairway with his escape shot, eventually making a bogey six.
In the group behind, Scott found the green in two with a towering iron shot as Every looked on, only to then three-putt for par to remain two behind.
Every then found a greenside bunker on the 17th but saved par after his recovery shot slammed into the pin and somehow stayed out. Scott's challenge ended when he failed to save par from the same bunker but Bradley fired a superb approach to 10ft and holed for birdie.
A bogey from Every on the 18th then left former US PGA champion Bradley needing a birdie there for the second day running to force extra holes, but his long-range attempt slid just past the hole.