Arnold Palmer Invitational 2016: Friday Leaderboard Scores and Highlights

Jason Day led by only one stroke through 18 holes of the Arnold Palmer Invitational and managed to push his advantage to two shots thanks to an exceptional performance during Friday's second round.

The reigning PGA Championship winner fired a bogey-free, seven-under 65 to get to 13 under overall at Bay Hill Club and Lodge in Florida—good for a 36-hole edge over Henrik Stenson.

Beginning on the back nine, Day made all pars save for birdies at Nos. 12, 16 and 17. The former two holes, where the Aussie capitalized on two booming fairway drives well over 300 yards to set himself up for easy fours, are par fives.

The PGA Tour's official Twitter feed did a fine job showcasing the best moments from Day's round:

A lengthy birdie putt at the par-three 17th allowed Day to turn in three-under 33. He managed to do one stroke better on the front, closing out his round in style with another birdie bomb at No. 9.

Fox Sports' Shane Bacon reacted to Day's dazzling display:

Day's magnificent performance coincided with a curious post-round development, as reported by GolfDigest.com's Dave Shedloski:

Highly unlikely Day is on any kind of enhancer. He's simply found his groove again in all areas of his game and is leading in strokes gained-putting.

The flat iron has been about all that's held Stenson back in recent years. He's in prime position to challenge Day and will be paired with him on Saturday after a second straight ball-striking clinic in Round 2.

Stenson finished second at Bay Hill last year, so it's evident he enjoys this layout and ought to be able to draw on his prior positive experience. His only bogey of the tournament thus far came on Friday at the par-three second hole, but it's otherwise been a flawless performance from the Swede.

Only one stroke further behind the pace is past U.S. Open champion Justin Rose. Boasting one of the purest swings on tour, Rose has quietly had a nice season thus far but hasn't really contended. That figures to change this weekend after his second-round 66 to get to 10 under.

Brian Wacker of PGATour.com was among those pleased to see such a star-studded trio at the top:

In danger of missing the cut after opening with a 75, Rory McIlroy bounced back in a big way with a 67 to vault up the leaderboard, though he'll still need Day, Stenson and Rose to fall back if he's meant to have a shot come Sunday.

McIlroy hit only eight of 18 greens in regulation Thursday but improved to 12 and enjoyed a fine day on the greens, as the PGA Tour noted:

As for the players within a bit more realistic striking distance of the lead, a quartet at eight under is tied for fourth. Among the group is Jamie Lovemark, who leads the field in strokes gained tee to green but must hole out a bit more often to challenge the elite competition ahead of him.

No Laying Up appreciated the aggressiveness Lovemark showed in attacking the par-five sixth with a monster drive that led to a two-putt birdie:

Lovemark has serious potential and is likely the best candidate among Kevin Chappell, Troy Merritt and Derek Fathauer to chase the leaders following a second straight four-under 68.

All the big names who are continuing to play at a high level on the Florida Swing should be lauded, because the Masters is mere weeks away. It'd be easy for everyone to look ahead.

Many eyes will be on McIlroy to see how he handles the lead up to a career Grand Slam bid at Augusta National.

But with the way Day is playing, he is threatening to steal the show. He's currently emulating the form from the second half of last season, when he won four of six starts, including the PGA Championship and two FedEx Cup playoff events.

If Day is clicking to that degree, the green jacket may well be his, denying Stenson of a potential first major and McIlroy of joining some of the most exclusive company in the game's history.

Post-Round Reaction

In reference to the aforementioned form that got him to No. 1 in the world for a time last year, Day said, per ESPN.com's Jason Sobel, "The ultimate goal this year, I guess, is to try and get back there...I hate playing bad golf, I really do. That's why I work really hard."

Rose was quite pleased with his round but hinted he needed to fare a bit better on approach shots:

Speaking to ESPN.com's Bob Harig about his second-round thought process and where he stood, the often candid McIlroy provided a realistic assessment for his Bay Hill outlook:

"

I saw [Day] ahead of me and I got to maybe 8 behind at one point. And I was thinking if maybe I could get to 6 behind for the weekend...and then I'm 11 behind. Maybe I can make up a little ground. But 67 was a great start today. It could have been better. If I can go out at the weekend and shoot a couple of scores similar to that, it might not be good enough, but it'll still be a good comeback from what [I shot] yesterday.

"

As for the Nike-signed Lovemark, his work with swing instructor Chris Como—Tiger Woods' most recent coach—has paid dividends, as he explained to GolfChannel.com's Will Gray.

"As far as I hit it, reaching a lot of par-5s in two, I have a lot of scrambling shots around the green," said Lovemark. "So Chris and I have put in some work, and I’m swinging it a lot better than I have the last three or four years. Much more consistent."

Lovemark added, "I'll have to make a lot of birdies. [Day]'s certainly making a ton. I mean, 13 under with a double, he’s playing great. He's one of the best players in the world for a reason, but there’s still a lot of golf left for the both of us."

The 28-year-old American has yet to win on the PGA Tour, but what a way it would be to break through if he managed to top Day, Stenson and Rose over the weekend.

Note: Stats and information courtesy of PGATour.com unless otherwise indicated.