Set for a Saturday finish in the US to avoid going head-to-head with the NFL Conference Championships, Day will begin the final round level with American Will Zalatoris (65) at 14-under, one shot clear of world No.1 Jon Rahm (72) and Englishman Aaron Rai (68).

A two-time winner at Torrey Pines, Day knows what it takes to win on the famed South Course yet admitted that recapturing winning feelings might be more unfamiliar.

Currently ranked No.129 in the world, Day has not won since the Wells Fargo Championship in May 2018 and has not featured in the top-three on Sunday once in that time.

He has spent much of the past few years trying to develop a swing that places less stress on his lower back and said that there have been times he has questioned whether the work he was doing had a successful end point.

“I’ve been saying that I’ve been close for a long time, that’s what I’ve felt like I’ve been saying,” said Day.

“It’s been a long two-and-a-bit years not really being in contention or having a good shot at winning a tournament, but I think overall I’m pretty pleased with how things are progressing swing-wise, body-wise.

“I’m glad that I’ve given myself a chance at it tomorrow. That’s the ultimate goal is to put myself in the position where I can win tournaments.

“I feel like it’s been a long time. Even though I’ve had some good finishes here and there in the last three years, it’s been difficult to know that like, hey, do you want to keep pushing it, because it’s painful either way.

“It’s painful if I walk away, it’s painful if I keep pushing on, so I just had to kind of suck it up.

“You’ve just got to understand that it’s going to take a long time for me. It may not for other guys, but for me it’s taken a while and just stay patient with myself and just stay positive as much as possible because sooner or later it’s going to change.”

A winner of 12 PGA TOUR titles and a former world No.1, Day left his run late to make an impression on the third round leaderboard.

An approach shot from 170 yards to eight feet set up birdie at the par-4 fourth to reach 10-under and a pitch shot to four feet at the par-5 ninth set up a second birdie to make the turn two-under on his round and 11-under for the tournament.

A bogey at 12 was offset by a birdie at the par-5 13th and then the 34-year-old closed his round with three straight birdies to post 67 and join Zalatoris on top.

It’s a position he has not occupied for a number of years but Day knows his history at the venue will provide some level of comfort as he seeks to rejoin the winner’s circle.

“I can’t be overly excited about it,” Day said of his lofty position.

“I’ve been in the position before. I just know that everyone’s going to be super pumped to be either in the final group or in and around that.

“I’ve just got to forget what other people are doing. If I can go out there and just play within

myself, then I should be able to give myself the opportunities.

“I just can’t get inside my head too much, I’ve just got to go out there and be patient.

“It’s nice to be able to be in the position, but like every position that you get into tournament-wise, kind of feels new.

“It’s nice to be able to know that I’ve done it on the golf course twice, not only in regulation but also in playoffs, but tomorrow’s a new day and you don’t know what’s going to come.

“I’ve just got to kind of get a good rest tonight, get into it tomorrow and just be patient.”

Winner at Torrey Pines in 2020, Marc Leishman (69) is the next best Aussie in a tie for 19th with Cam Davis (71) moving up into a share of 47th with one round to play.

On the LPGA Tour Victorian Su Oh will begin the third round tied for 10th and six shots off the lead shared by Kiwi Lydia Ko and American Danielle Kang.

Oh had five birdies in her round of 70 as playing partner and Hall of Famer Karrie Webb shot 72 to comfortably qualify for the weekend in her first start in 15 months.