Vikki Laing, who turned 36 earlier in the week, was next best among the Scots with a level-par 73 to sit joint-29th.
McIlroy admitted as much afterwards to the Golf Channel. My irons weren't quite where I would have liked, didn't give myself enough close birdie opportunities.
"Eleven could have turned into a 5 or a 6 pretty quickly but I got a little bit of a break with my ball in the shallow end of the water and I was able to take advantage of that".
"I couldn't think of a better way to honor him than to be there on Sunday afternoon, finishing the way he would", Snedeker said.
"I scrambled really well", he said.
"I know what I'm doing". It was just a matter of putting it all together and today I did. "In the end of previous year I was just worn out".
In the first staging of the event since the September death of Palmer, his grandson Sam Saunders missed the cut by one stroke. "It's right up there with competing in a major championship, there's no question".
Still, class will out, albeit infrequently in McIlroy's case yesterday. "I didn't hit it good off the tee".
Hoffman's birdies on No. 16 and 18 were putts from 45-feet and 71-feet away, respectively.
Making just his third start of 2017 due to a rib injury, McIlroy bogeyed his first two holes after a wild tee shot on the 10th and another errant drive on the next, but bounced back with a birdie on the 12th and an eagle on the 16th.
Was that the sound of an engine purring into the high revs?
Greg Chalmers is another Australian in the mix and, although five shots from the leaders and in a share of eighth position, he is not without hope of contending over the final stages tomorrow.
Rory McIlroy and Tyrrell Hatton tied for fourth at 9-under.
The nightmare round left him tied-19th on the leaderboard and eight shots behind joint-leaders Kevin Kisner and Carey Hoffman.
European Ryder Cup player Matthew Fitzpatrick took up the baton on behalf of the worldwide players, shooting 69 to lie second on eight under par before the afternoon wave of players came out to play.
"It was a very up-and-down day", the world number 32 said.
It came in the shape of a four-under-par 68 - one of the best early scores on the second day - that had jumped Laird, a three-time victor on the PGA Tour and back close to top form after suffering a bit of a dip, up 59 spots by the time he finished.