Jon Rahm’s first round as Masters champion failed to repeat his Augusta heroics as he carded a one over par 72 in the first round of the RBC Heritage.

The world number one struggled for consistency as he hit just seven fairways on a weather-hit day at Hilton Head, finishing eight strokes off the lead of Viktor Hovland.

“I hate to make excuses, but a couple of the swings towards the end were my body being tired and surprised me,” Rahm said following his opening round.

“I’m hoping tonight is where I start turning things back around and start feeling a bit better.”

RBC Heritage GolfViktor Hovland, left, of Norway, shakes hands with his caddie after his first round (Stephen B Morton/AP)

Hovland, who shared the lead with Rahm and Brooks Koepka after the first round at Augusta en route to a tied-seventh finish, shot an opening 64 despite laying up into the water at the 15th.

Remarkably, playing partner Justin Thomas managed the same feat.

“That was really bad,” the Norwegian admitted. “I just picked the wrong shot.”

Despite that error and missing birdie putts from inside 15 feet on three of his first four holes, he hit 14 of 18 greens in regulation to open a one-shot clubhouse lead over American Brian Harman.

England’s Aaron Rai and former US PGA champion Jimmy Walker were also a shot off the lead on six under, but were among six players yet to finish when darkness ended play on a day which included a 90-minute weather delay.

English pair Justin Rose and Matt Fitzpatrick were among a group a shot further back after opening 66s.

Tyrrell Hatton opened with a three under par 68, one better than Tommy Fleetwood with Ireland’s Shane Lowry, European Ryder Cup captain Luke Donald and fellow Englishman Danny Willett going around in 70.