Rory McIlroy's opening round at the PGA Championship was nothing short of a nightmare, and the blister on his right pinky toe was the least of his concerns. The four-time major champion stumbled to a 4-over 74 at Aronimink, a score that has historically been a death knell for title hopes—only Payne Stewart in 1989 has managed to win the PGA Championship after starting with a 74.

McIlroy's round unraveled in spectacular fashion, with five bogeys over his final six holes. The trouble started early and never let up. He struggled mightily off the tee, a recipe for disaster at the demanding Aronimink layout, and was tentative over his putts, missing three from inside 7 feet that could have salvaged his day.

When asked by a PGA of America moderator to describe his opening round, McIlroy's response was a single, four-letter word—a clear sign of his frustration. Earlier in the week, he had downplayed the strategic demands of the course, saying "strategy off the tee is pretty nonexistent. It's basically bash driver down there and then figure it out from there." But on Thursday, that approach backfired spectacularly.

For much of the day, McIlroy was hanging around par alongside playing partners Jordan Spieth and Jon Rahm, which was respectable given the testing conditions. His only bogey on the front nine came on the opening hole from the right rough, where he could only scoot the ball down the fairway. But the wheels came off after the turn. A 30-foot birdie putt on the par-3 fifth briefly steadied the ship, but it was all downhill from there.

"I missed the fairway right on 4, the fairway right on 6, the fairway right on 7, fairway right on 9," McIlroy explained. "From there, it's hard. I didn't have great angles, either. Then obviously you start missing it just off the edges of these greens, it gets tricky."

This isn't the first time McIlroy has opened a major with a 74. Last year at Quail Hollow in the PGA Championship—his first round as Masters champion—he also posted that score, though the frustrations then stemmed from discovering his driver face had become too thin to conform to regulations. This time, the issues were purely on the course, and they left the world No. 3 with a mountain to climb if he hopes to keep his calendar Grand Slam dreams alive.