Misfiring number one Jon Rahm slumps in PGA Championship opening round

The Spaniard was widely perceived as a favourite having been on a hot streak, picking up three wins on the Tour this year before donning the green jacket for the first time in April.

But Rahm appeared to have lost his Augusta finesse as he recorded six bogeys plus a double-bogey on the par-four seventh after opening on the back nine with a birdie.

Rahm earned a meagre slice of redemption with a birdie on his penultimate hole to card a 76 for the day.

"The main thing on this course is hitting the fairway. If you put the ball in the fairway you can actually give yourself a lot of good chances," he said.

"That's what I didn't do. Obviously, the first ... six holes of the day I played really good. Put myself in a good spot and after that I found myself battling."

The 2021 US Open champion also levelled criticism at his short game, lamenting a trio of flubbed putts that could have put him in better standing heading into Friday's action.

"The only thing I can look back on myself is the three short putts I missed on the back nine... If I make those putts, I shoot 3-over which is not the worst-case scenario," said Rahm, who would not count himself out despite his poor showing.

"If I can somehow manage to putt a low one tomorrow and find myself close to even par ... going into Sunday, I think I'll have a decent chance."