Day - competing in his 9th PGA - mixed 4 birdies with one bogey at Bellerive Country Club in St. Louis, Missouri to be poised to challenge for a second Wanamaker Trophy.
The Queenslander's only bogey came at his 15th hole (the 6th of the course) and was a result of perhaps a thinking mistake rather than poor execution.
“It was good,” said Day soon after his round. “I think I hit 12 fairways and 17 greens. It was nice. I definitely gave myself a fair share of birdie opportunities out there but didn't quite capitalize on the front side.
“Being able to come back with birdies on 7 and 8 after I bogeyed on 6, even though I hit - I hit a great shot into the par 3, just straight over the green. Hit a 5 iron from 221. I wasn't thinking that was going to go that far. But, fortunately, I'd much rather be in the back bunker than in the water. Overall, I'm very happy with how things progressed out there."
Day was even happier with his round given that he was struggling with a cold coming into the event and his preparation was not quite what it might have been.
“I was a little bit under the weather coming in. I missed the Champions Dinner because of it, because my wife came home from The Open Championship with a cold and passed it on to me because she's such a giving person, which is great. So I had a little bit of a cold. It was a man cold, to be honest. Yeah, I did some chipping and putting on Tuesday.
“My plan was to go out and play 18 holes on Tuesday and just take Wednesday off, but I couldn't do that, obviously, because of the rain. So I chipped and putted a little bit on Tuesday and then played 18 holes and pretty much have just been resting up the whole time.”
Day said the Bellerive layout - which hosted the 1992 PGA and last hosted a PGA Tour event in 2008 - fits his eye.
“It's straight up in front of you. There's nothing really tricky about this golf course. It just can be brutally long.
“If you can ball strike your way around this golf course, you'll walk off thinking it's pretty simple. If you struggle a little bit off the tee, then it obviously makes it harder.”
Marc Leishman began the day with a bogey at the 2nd but soon recovered with three birdies before the turn. He essentially trod water on the way in but finished with a round of 2 under 68 to be 4 from the lead.
Adam Scott is at even par 70 while Arizona-based but South Australian-raised teaching professional Craig Hocknull recorded a respectable round of 2 over par 72 in what is his very first major championship having gained a start through a national club pro event.
“I thought it was great," Hocknull said afterwards.
"I wanted to start making more birdies, but I felt like I just needed to keep playing it smart, keep doing the things I needed to do, and I mean I really only mishit one shot and that was a little club indecision on 10, put me in the bunker and then I didn't get up-and-down for my par.
“Overall I felt like I played great, I felt like it was very solid. I think I'm, I don't know, 46th or whatever it is at this point, so for me to be in that position and really not play my best but play good, I think that's a great place to be.”
Cameron Smith made a horror start to his day dropping 4 shots in his opening six holes and although able to play his final 12 holes in even par his round of 74 has him needing something very special tomorrow to make the weekend.
New Zealander Ryan Fox completed the down under contingent and did very well with an opening 68, birdies at his final two holes allowing him to re-establish himself in contention after dropping two shots early in his back nine.
SIGNATURE HOLES: 17TH AT GAINSBOROUGH GREENS (QLD)
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