The former World No. 1 ended seven shots from the eventual winner, Chez Reavie, though only three shots out of second place.
A double-bogey and bogey through the middle stages of his opening nine today cost Day any realistic chance of finishing a lot closer and, in the end, a final nine of 32 was needed to finish where he did.
Day was asked about the week and his plans moving forward.
"Just get back and practice. I need to improve the putting. Even though I hit a lot of good, quality putts, just not quite happy with it but I hit 88 per cent of greens this week.
"Shot 1-under today and hit 17 greens. The only mistake I made was on the par-3 and I misshit it and pulled up short in the water.
"So there are a lot of positives coming from this week and I feel really good about my game. Very, very motivated to go back and practice this coming week and get ready for the 3M."
Former winner of the event Marc Leishman finished as the next best Australian tied for 21st, while Cameron Davis was 43rd.
It was Reavie's first PGA Tour title since the 2008 Canadian Open and following a 3rd place finish at last week's US Open his game appears to be close to its very best.
Despite his four-shot winning margin, it was not quite as simple as the gap would suggest with Keegan Bradley getting within one shot before a double bogey at the 17th put paid to his chances.
When Reavie then birdied the 17th himself, it was all but over.
In the end, Bradley and Zack Sucher tied for 2nd place, Zucher producing a final nine of 30 to recover from a mid-round mishap and record his best ever PGA Tour finish.
"Yeah, you know, going and being in the second to the last group at the U.S. Open last week, that definitely gave me a lot of confidence coming into this week, and in particular into today," said Reavie who has had his share of injury issues over the years.
"I played really well on Sunday at the U.S. Open, and I tried to treat this the same as I did then.
"I went through some injuries; had long years there in the middle. It was great because it gave me good perseverance and good perspective of what life is and what golf. I enjoy every minute of every week I'm out here now, and I don't think I would necessarily be that way if I didn't go through those tough times."
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