Jon Rahm toils as Rory McIlroy battles hard in opening round of US PGA Championship at Oak Hill Country Club

Masters champion Jon Rahm found it tough going in the opening round of the US PGA Championship, as Rory McIlroy battled to keep his hopes alive.

The Spaniard made a superb start with a birdie on his opening hole, his 10th, and was solid for six holes.

But from the 16th, his seventh, the round unravelled for the world No. 1. He went on a run of five bogeys in six holes to drop off the pace.

A double bogey saw Rahm drop to seven-over, but he made an excellent birdie on his penultimate hole to sign for a 76.

McIlroy’s round was in danger of going the same way as Rahm’s, but he showed tremendous resolve on a day when he struggled off the tee.

After being one of the form players heading into the opening major and being full of confidence about completing the career Grand Slam, things have gone south since a missed cut at Augusta.

McIlroy returned to action at the Wells Fargo Championship and failed to figure. Worryingly, he was battling a two-way miss which is a golfer’s worst nightmare.

In the opening round of the second major of the year on Thursday, he hit only two of 14 fairways but somehow scrambled superbly around a course with penal rough.

McIroy dropped to three-over at one stage, but after putting in for par from off the green on his 12th hole he gained some momentum.

Three birdies and a further bogey followed in a round of 69, as McIlroy kept himself in the tournament.

McIlroy said following his round that he was battling illness, but felt better than the previous day.

“I’m fighting something,” he said. “I thought I got a great night’s sleep last night, and I look at my Whoop (fitness watch), and I was 22% recovery, and my skin temperature was 3.5 degrees higher than what it’s been. I’m fighting something. But I actually feel better today than I felt yesterday, so plenty of water and a bit of rest, I’ll be fine.”

Commenting on his opening 18 holes, McIlroy said: “I’m going to need to play a lot better than that if I am to have a future in this tournament. You are in for a tough day when you keep hitting it out of the rough like I was today.”

Scottie Scheffler is the other member of the current big three in golf, and McIlroy and Rahm find themselves four and nine shots respectively behind the American who set the early clubhouse lead with a round of 67.

Long and difficult golf courses hold no terrors for Bryson DeChambeau, as he proved with US Open success at Winged Foot in 2020, and one of the star names of LIV Golf moved top of the leaderboard with an excellent round of 66.