Rory McIlroy was pleased to capitalise on "benign" conditions and make a promising start to the U.S. Open on Thursday.

McIlroy, on a high after a dominant Canadian Open victory last weekend, carded a three-under 68 in his first round at Pebble Beach to trail leading trio Rickie Fowler, Xander Schauffele and Louis Oosthuizen by just two shots.

The four-time major champion reflected on a job well done, knowing the course could become much more challenging.

"I think my average the first round in the last three years of this tournament is always 70.2. So I'm happy with this. It's my first round in the 60s at a U.S. Open since Chambers Bay in 2015," said the Northern Irishman.

"But it was out there. Benign conditions. It's a very soft start to a U.S. Open, which is a good thing, because you're completely in control of the golf course.

"They can do whatever they want with it from here. It's not as if you're starting with a course that's in the condition like a Sunday and then you get three days and it sort of starts to get away from you.

"If they want to dial it up and make it a little bit further, they just don't have to put much water on it tonight and we'll come out tomorrow and it will play a little bit trickier. From the scores I'm seeing, that's really what I expect for tomorrow."

He added: "In terms of set-up, maybe not the conditions, the fairways are very slow. The greens are quite soft still. But in terms of the set-up.

"I'm looking at the 13th fairway here. It's 50 yards wide, 45 yards wide from left-to-right. There's generous targets out there still.

"But all this golf course needs is just a little tweak here and there, and it can play a lot more difficult. So while the conditions are this benign and the golf course is still sort of soft and slow, you need to take advantage of it, and thankfully I did today."

Gary Woodland, Emiliano Grillo and Sepp Straka matched McIlroy's opening round, while Scott Piercy set the clubhouse lead with a four-under 67.