Rory McIlroy eased any concerns about the state of his game heading into the first Major of 2016 as Jason Day set an imposing clubhouse target in the Arnold Palmer Invitational.

Day added a flawless 65 to his opening 66 for a 13-under-par halfway total of 131, just one shot outside the tournament record shared by fellow Australian Adam Scott, Tom Watson and Andy Bean.

That gave Day a five-shot clubhouse lead over America's Jamie Lovemark (69), while England's Paul Casey carded a 67 to get to seven under.

McIlroy, who had opened with a three-over 75 rebounded with a five-under 67 to move to two under and inside the projected cut mark of level par.

“It would be nice to go eight under tomorrow,” joked Day, whose best score at Bay Hill before the start of the week had been 68.

Starting on the back nine, the USPGA champion birdied the 12th, 16th and 17th to reach the turn in 33, before picking up four more birdies on the inward half and closing his round in style by holing from 35 feet on the ninth.

“I said after yesterday’s round I was just trying to stay patient and came out and started off really solid and kept it up,” the world number three added. “I drove the ball nicely, hit a lot of good quality shots into the greens.

“I had one kick-in on three but for the most part played the par-fives great again and just putted great. The two bombs that I holed today on 17 and nine definitely helped, but I felt like these sorts of scores were coming, I just had to be patient with myself.

“It’s very easy to get ahead of myself, especially with how I’ve played earlier this year. It hadn’t been that great and I get a lot of media saying ‘What’s wrong, what’s wrong?’.

“You can get a little bit caught up in it sometimes but you just have to make sure you’re doing the right things, you’re working hard, you’re working towards that goal and the last few days has been fantastic.”

McIlroy, who blew a four-shot lead in the final round of the WGC-Cadillac Championship, had kept pace with Day in the group ahead for much of the round thanks to six birdies in his first 14 holes.

However, the world number two failed to birdie three of the four par fives and eventually had to settle for a 67 after dropping his only shot of the day on the seventh – his 16th hole – after missing the green off the tee.

McIlroy admitted he had been shocked by starting his first round, with a double bogey after driving out of bounds, telling Sky Sports: “Yesterday was a weird one because last week at home I was hitting the ball so well.

“My practice sessions were really good, I was playing well and then you tee it up in your first competitive round in a week and you hit it out of bounds left. It was a bit of a shock to the system for me because I was wondering where it came from.

“I didn’t really think anything of it and then a few more drives started to go left and I just need to work on it last night and figure it out on the range and thankfully I was able to figure it out and straightened it out today.”

Despite being 11 shots behind Day, McIlroy has not given up all hope of getting into contention over the weekend, adding: “I need to set myself a target and try to get to that, try to emulate what he has done over the first two days.

“If I was to go out and shoot a couple of 66s over the weekend I don’t feel like I would be too far away. I can’t think about Jason being 11 shots ahead of me, I have to make as many birdies as I can and even if that’s not good enough at the end of the week, I can take a lot of positives and a lot of confidence from that going forward.”

Graeme McDowell missed the cut after he carded four bogeys on his back nine in a four-over-par 76 as he finished on three over.