Just 24 hours after claiming if he had Rory McIlroy's distance he would be one of the best players in the world, PGA club professional Michael Block opened with a shocking first-round 81 at the Charles Schwab Challenge.
Block, 46, received an invite into this week's PGA Tour event off the back of his T15 at the US PGA Championship last week.
UPDATE: BLOCK FINISHES LAST AT CHARLES SCHWAB CHALLENGE
That was the best finish of any PGA pro in the championship's history since 1986.
But despite being full of confidence heading into the first round at Colonial, Block very much came back down to earth with a disastrous 11-over 81.
That leaves him in last place of the 120 players in the field.
Block opened with three straight bogeys, and despite responding with a birdie at the par-3 4th instantly gave it back with another bogey on the 5th.
The American made the turn with a birdie on the par-4 9th when nearly holing out for eagle but that was to be his final highlight of the day.
Block bogeyed 11, 12 and 13 and then went double-double on 15 and 16 to fall to 9-over par.
On the 15th, Block chunked a wedge into the bunker and then skulled his next shot over the back of the green.
He parred the 17th but then made a mess of the 18th when sending his tee shot left into the trees and that led to another double bogey.
England's Harry Hall surged to the top of the leaderboard following an impressive round of 8-under 62.
Hall enjoyed a flawless round of golf featuring five birdies on the front nine and three on the back.
He leads by three strokes over a resurgent Harris English, who carded a 5-under 65.
Hall only turned professional four years ago.
Elsewhere, World No.1 Scottie Scheffler and defending champion Sam Burns played alongside each other en route to rounds of 3-under 67.
Max Homa also went round in the same score.
Of some of the other tournament fancies this week, Viktor Hovland (1-over), Tony Finau (2-over) and Collin Morikawa (3-over) all have plenty of work to do in order to get themselves back into contention for the title.