Japan's Hideki Matsuyama produced a stunning second round 64 to claim a share of the lead at the USPGA Championship on Friday.

Last week's WGC-Bridgestone Invitational champion was not fazed by the poor weather conditions and he birdied five of the last seven holes.

His round was suspended for one hour and 42 minutes due to a thunderstorm but Matsuyama claims it gave him the rest he needed.

He is tied with American Kevin Kisner on eight-under par and the duo are two shots clear of third-placed Jason Day.

Francesco Molinari, Louis Oosthuizen and Chris Stroud are all tied in fourth on five-under and Matsuyama admits his low-scoring round did surprise him.

"I was grateful for the rain delay because I was getting tired,” he told the PGA Tour. "I was able to lay down in the locker room and get some rest.

"I think what was making me tired was I wasn't hitting my driver like I wanted to. I was hitting fairways but I wasn't getting the crisp contact that I was hoping for with my driver.

"The greens here at Quail Hollow, as you know, are really fast. And there's a lot of putts that honestly, I'm not trying to make. I'm just trying to get it up near the hole, and a lot of them are going in."