Norway's Viktor Hovland, Spain's Jon Rahm and American Brooks Koepka shared the clubhouse in the first round of the Masters on Thursday after taking advantages of easier-than-usual conditions to card seven-under par rounds of 65.

Rain in recent days has softened Augusta National, making the often rapid and challenging greens much more benign, and the trio seized a two-stroke lead over American Cameron Young and Australian Jason Day.

Ireland's Shane Lowry, Americans Xander Shauffele and Gary Woodland, and Australian Adam Scott were three strokes adrift after shooting 68.

Hovland, who was playing in the same group as Woods and Shauffele, got off to a flying start with an eagle on the par-5 second hole, where he followed up a brilliant iron shot with a 25-foot putt.

Further birdies came on the ninth, 11th and 13th holes but the Norwegian was less tidy in the final five holes, finding himself in trouble on the par-5 15th, where he went far to the left but he was able to scramble to make par as he ensured he finished bogey free.

"I would have taken that. That was pretty fun. My game's been feeling good," he said. "But to shoot a 65 bogey-free out here, some things have to go your way. It's not like you can just step up and have that handed to you. So I definitely had some things go my way today but also hit a lot of great shots."

Five-time Masters champion Tiger Woods battled through constant leg pain to fire a two-over par 74 in the opening round, his worst 18-hole start at Augusta National since 2005.

"I felt like I drove it good," Woods said. "I just didn't do the job I need to do to get the ball close. Today was the opportune time to get the round under par and I didn't do that."

"I'm good," Woods said. "Hop on the left leg is fine. If I did it on the other one, not so fine."

(With input from AFP)