An elated Young said the mentally taxing nature of Sawgrass's unforgiving 7,352-yard layout had made Sunday's victory extra special.
"It's absolutely exhausting," Young said.
"This place has had my number the last few years. I've never really had a good finish here. It is incredibly taxing.”
"Every shot all day long you can get yourself into trouble. There's no easy ones. There's no givens. And you're going to make mistakes.”
"It's a great test of will, a test of patience and obviously a test of hitting some good shots. I feel like I did a lot of those things really well this week."
Young, who had drifted off the pace after a double-bogey on the 18th in Saturday's third round, conjured a moment of magic on Sawgrass's notoriously tricky par-three 17th to thrust himself into contention.
Trailing Fitzpatrick by one shot with two holes to play, Young drilled his tee shot onto the water-encircled island green to 10 feet and then rolled in the birdie putt to leave it all square heading to the 18th.
Young quickly erased the memory of his double-bogey nightmare on the 18th from the third round with a majestic tee shot into the center of the fairway.
His second found the back of the green and although he missed his birdie chance, Fitzpatrick could only bogey to give Young the biggest title and payday of his career with a $4.5 million winner's check.
Young's closing 68 left him on 13-under 275 for the tournament, with Fitzpatrick one adrift on 12-under.
Fitzpatrick closed with a 68 but later brushed off any suggestion that the ferociously partisan final day crowd —- who had bombarded him with boos and chants of U-S-A! on the 18th tee — had been a factor.
The Englishman contrasted Sunday's galleries with the bedlam at Bethpage Black last year during the Ryder Cup.
"Listen, the crowd, that was literally child's play compared to Bethpage," Fitzpatrick said.
"If they think that that was anything, then they need to reassess. Get yourself up to New York.”
"That's how it is. I would hope it's the exact same — well, it probably wouldn't be because we're a little bit more polite in Europe — but I would hope it would be of similar intensity in Europe. It's funny to me. I find it hilarious."
Xander Schauffele took third place with a three-under-par 69 that left him on 11-under, while Scotland's Robert MacIntyre was a shot back on 10-under after a closing 69.