NAPLES, Fla. – Lydia Ko and Jason Day – two former world No. 1s on their respective tours – took the lead at the Grant Thornton Invitational with a day’s best 6-under 66 in the alternate shot format. Even more impressive given that the pair met for the first time earlier this week.

“It’s fun, but I still want to win and I’m sure Lydia wants to win, too,” said Day. “We could definitely use a win like this or even a good finish to propel us into next season … I was saying to Lydia there’s certain things we’re both working on in our swings that we want to try and work under pressure.”

Ko and Day hold a two-shot lead over overnight leaders Tony Finau/Nelly Korda (70) and Leona Maguire/Lucas Glover (69).

While this week’s event is unofficial, the purse of $4 million is the highest on the LPGA outside of the majors and the CME Group Tour Championship. The winners will receive $1 million ($500,000 each).

Rickie Fowler and Lexi Thompson vaulted up the board into a four-way tie for fourth after a 4-under 68. Thompson’s ace on the par-3 16th from 158 yards was her 11th career hole-in-one. (She has five in official LPGA tournaments.)

“Ended up taking my 7-iron, which is my like 62 to 65 club,” said Thompson, “and backed up two club lengths from the tee marker and just tried to hit like a 3/4 hole.”

Thompson said she kept the ball and will add it to a collection she keeps in a box at home from other aces and a pair of albatrosses.

“Never left the flag,” said Fowler of the shot of the day.

ACE FOR LEXI

@Lexi and @RickieFowler are now one back of the lead @GTInvitational! pic.twitter.com/zlPleOSM5k

— PGA TOUR (@PGATOUR) December 9, 2023

The 16-team event will change formats once again for Sunday’s final round as modified alternate shot goes into play. Both players will tee off and then play each other’s ball for the remainder of the hole.

“I have no worries,” said Ko of the new format. “Jason’s pretty much hit 90-something percent of the fairways. I’ve gotten to hit his ball today and he’s gotten to hit mine. In ways, this was like a pre-warm-up for what tomorrow’s going to be.

“I was joking before I knew what it was going to be like, ‘Oh, man, Jason’s got to hit from places he’s never hit from, like maybe a little further back.’ We’re actually going to do that.”