The 68-year-old fell two shots short of making the cut on his 43rd and final appearance in the season’s opening major.
He was overcome with emotion walking up to the last green along with his caddie Neil Oxley, having been cheered on to every tee and green earlier in the round.
After holing out for a par-4, Watson touched his heart and pointed to the patrons in a thank-you gesture.
“I’ve been blessed to be able to play here and have fans,” he said. “I hope I entertained some fans here or the patrons here. I appreciate their applause for me and how they treated me today out there.
“There were lots of hats off to Tom today. It was really pretty special and it was heart-warming.”
Watson has now bode farewell to all four majors, having taken his final bow in the Open Championship at St Andrews last summer.
“Well, there’s some melancholy to it to a degree,” said the 1977 and 1981 winner of his decision to no longer be part of this event.
“I’m a realist and I can’t play this golf course anymore. If I could still play this golf course, I wouldn’t be retiring rom playing the Masters. That’s the truth.
“I know that next year, six weeks before the Masters starts, I’m not going to have anything to do because I don’t have to prepare for the Masters like I always have for my entire career.
“Six weeks in advance, hit those key shots at 12, at 5, at 10. Practice those iron shots that you want to play. And I’m not going to be doing that anymore.”
The only disappointment for Watson on his farewell round here was that he was deprived of his favourite chocolate bar on the back nine.
“As part of my routine, as I go up 11 I have a Snickers bar and have a drink and it gets me through the back nine,” he said.
“That’s been my routine for 30 years out here - but they were out of Snickers bars today.”