World number one and defending champion Jason Day is hoping his presence on the US PGA Championship leaderboard will affect the players in front of him after surging into contention on Friday.

Day dazzled during the second round at Baltusrol, carding an emphatic five-under-par 65 to close within two strokes of American leaders Jimmy Walker and Robert Streb.

After bogeying the third and double-bogeying the seventh, which saw Day drop to even par at the year's final major, the Australian birdied seven of his next eight holes to improve to seven under overall.

Day is now looking to use his status as golf's number one to unease his rivals heading into the weekend.

"I hope so. That would be nice," Day told reporters afterwards. "When guys are going to play good, they are going to play good. You look at Henrik [Stenson] and Phil [Mickelson] at The Open Championship. They kind of ran away with it.

"Doesn't matter who you are. These guys are all good out here. They deserve the right to be here because of how they played. Anyone on any given week can play well.

"For me to be able to keep putting myself on the top of the leaderboard, more so now than the last few weeks, definitely helps a little bit. But I've just got to kind of inch my way slowly.

"Obviously I don't want to give the guys at the top some shots when I'm making silly errors. So I just try to inch my way back into the tournament that way."

Of that eight-hole stretch, Day refused to dwell on it too much with two rounds still remaining in his bid to go back-to-back.

"If it was on a Sunday, it would be the best. But since it's on a Friday, it's just a good solid round," he said. "Getting myself in contention is where we want to be by Sunday and obviously playing and shooting 65 today is that one step closer.

"Saturday is moving day, as everyone knows. If I can have a good one tomorrow, it will come down to the last day. So it's always exciting to be in contention. I'm super stoked about what happened today."

Day added: "I parred 17 and 18 yesterday and did the exact same thing today. I was a little bit more conservative after the chip shot on 18, after seeing what Rory [McIlroy] did. I didn't want to do that and give a shot back. I made sure that I got it up there and gave myself an opportunity.

"The one on 17, if I birdied that, I was like stealing one really. I hit a terrible driver there and hooked it up in the grandstand, nice shot over the trees and hit a pretty good pitching wedge up near the hole. Unfortunately didn't hole that. I said before, I'm just trying to save them for the weekend. If I can do that, that would be nice."