(Reuters) - World number two Dustin Johnson eagled the final hole to earn a share of the lead with fellow American Luke List after the first round at the RBC Canadian Open on Thursday.

Johnson sank a 12-foot putt at the par-five 18th to cap a roller-coaster afternoon round that also included seven birdies, a bogey and double-bogey at sun-baked Glen Abbey Golf Club outside Toronto.

"I drove it in the fairway a bunch. That was definitely very helpful," the U.S. Open champion told Golf Channel after signing for a six-under-par 66 and a one-shot lead.

"Conditions were tough. The wind was blowing pretty hard and I felt like I played pretty well. I just made one bad swing, on 14 (into the creek). Other than that I thought I played really nicely all day long."

Defending champion Jason Day was also rewarded for his aggressive approach with a 69.

Day used his driver liberally and collected four birdies, along with a chip-in eagle.

After finishing a disappointing 22nd at the British Open on Sunday, Day spoke of how he was looking forward to returning to hot and dry North American weather. So far he has not been disappointed.

"With how dry everything is, it's almost better to get up there around the green with a wedge in your hand," the Australian world number one told PGATour.com, explaining his aggressive mindset.

"You miss the fairway with an iron off the tee, there's no chance of keeping it on the green anyway, so you may as well get it up close to the green. The greens were pretty firm and fast."

Leaders Johnson and List headed fellow Americans Kelly Kraft and Chesson Hadley, Spain's Jon Rahm and Canadian amateur Jared du Toit by one shot.

List, ranked 309th in the world, compiled his six birdies with a minimum of fuss, picking up a stroke at each of the four par-five holes.

“I was able to birdie all the par-fives, so I was happy with that,” List said. “With my length, I just try to get it in play off the tee and have a scoring iron into the par-fives.”

Du Toit, meanwhile, found himself in lofty company after a round that included an unlikely eagle from 154 yards from a fairway bunker at the par-four 17th.

The 21-year-old from British Columbia, a college golfer at Arizona State, is not quite ready to contemplate the possibility of becoming the first Canadian to win his national open since 1954, preferring instead to just enjoy the moment.

“It was awesome,” he said.

(Reporting by Andrew Both in Cary, North Carolina; Editing by Frank Pingue)