Tournament host Tiger Woods signed for a 72 to bring up the rear in the 18-man field at two under.
But the tournament is wide open, and more than one player referenced Rickie Fowler's 61 previous year to win.
Gary Woodland, who was over par toward the end of his opening round, had a 67 and suddenly is only two shots behind.
The world number 33 took a three-shot lead over his fellow Australian into day four of the European Tour-sanctioned event at the Royal Pines Resort on the Gold Coast, but it quickly evaporated.
"That's just part of the injuries I've had and the aging process and trying to deal with that and compete". "I think the best way to describe it, having five par 5s and two relatively short par 4s, out of those seven holes I got six birdies". "But I don't think they did a year ago, and Rickie shot 11 under, right?"
Advantage Finau, at least over the last two days.
"At the same time, three-under (on Saturday), tied for the lead, I would have taken it at the start of the week". He still was only four shots behind, along with Xander Schauffele (66).
Dustin Johnson and Patrick Cantlay are tied for third on nine under, with Tony Finau a shot further back in fifth. The Sweden made eagle on the par-5 15th, followed that with a triple bogey on the 16th, and then responded with an ace on the par-3 17th.
He isn't putting a lot of stock into an event, and he wasn't about to make any comparisons to his return to golf in the Bahamas a year ago. He said, "I also use it as a learning curve because you can learn all these great things that all these great players have done, and use them for yourself". Today was probably the best I've felt physically this week. I'm extremely pleased." Summing up his year, Rahm said, "As I said, this year was not so much about golf, it was about me as a person, so to win as many times as I did last year, it just shows that when I get into contention, to me nothing else matters.
While Tiger Woods flopped again, Jon Rahm soared to victory at the Hero World Challenge on Sunday.
At the end of the third round at Albany Golf Club, Finau and Rahm were each holding a two-shot lead atop the leaderboard at 13-under along with Henrik Stenson. While it was a somewhat poor end to the year - finishing second to last at one under par, 19 strokes behind victor Jon Rahm - 2018 was far from a failure for Woods.