HILTON HEAD ISLAND, S.C. -- England's Aaron Rai birdied two of his final three holes to shoot 8-under 63 and take a one-stroke lead over Viktor Hovland after the first-round of the rain-delayed RBC Heritage on Friday.

Rai was among six golfers who couldn't complete play due to nearly 90-minute stoppage because of rain on Thursday.

Rai rolled in an 11-foot birdie putt on the 16th hole to tie Hovland soon after the re-start. He took the lead with a 17-foot birdie putt on Harbour Town Golf Links' famed No. 18 lighthouse hole.

"It feels good," Rai said after finishing. "Played really nicely. Can take a lot of positives from the way that we played tee to green and made a few nice putts as well."

Hovland had opened with a 64 on Thursday and was seeking a first-round lead for the second straight week after tying for first through one round at the Masters.

Two shots behind were Brian Harman and Jimmy Walker at 65.

Six others were another shot behind at 66, including reigning U.S. Open champion Matt Fitzpatrick, U.S. Ryder Cup captain Zach Johnson, Justin Rose, Scott Stallings, Sungjae Im and Joel Dahmen.

Masters champion Jon Rahm got off to a slow start with a 1-over 72. Rahm is back on the course for the second round as he tries to get back into contention.

Rahm acknowledged the fatigue from Augusta National, and it didn't help that his Thursday afternoon included a rain delay of nearly 90 minutes. He never got comfortable on a course he had competed on only once before.

"I hate to make excuses, but a couple of the swings towards the end were my body being tired and surprised me," Rahm said.

The RBC Heritage is the sixth designated event this year on the PGA Tour, meaning an increased purse -- up to $20 million from $8 million a year ago -- and many of the world's best, like Rahm and Hovland, in the field when they may have otherwise taken a post-Masters break.

Harman is from nearby Savannah, Georgia, and has played this event for 12 straight years. He missed the cut at the Masters, then took the weekend off and didn't touch a club until arriving on Hilton Head.

"I killed a pig Friday night at my farm, and I killed a turkey Saturday morning," Harman said. "I didn't hit any balls until I got here Tuesday."