NAPLES, Fla. — Sei Young Kim was on the verge of taking all the drama out of the chase for the richest payoff in women's golf history.

She opened with three birdies in seven holes Saturday in the CME Group Tour Championship as her challengers either stalled or faded. She led by five shots before making the turn.

Kim hit the brakes.

Nelly Korda hit the gas.

When the third round ended at Tiburon Golf Club, Kim had to settle for a 4-under 68 and a one-shot lead over Korda with one round remaining to see who wins the $1.5 million.

Both made it sound as though it will be just another round of golf.

Then again, no one in LPGA Tour history has ever played for this much cash. It's more than either of them has made all year.

"I had a pretty solid round front nine," Kim said. "But back nine was little tough to focus. I kept thinking about future, so I was like, 'Nope, Sei Young. Stop thinking. Focus on it.' I had a lot of chances back nine. Going to practice and ready for tomorrow."

Korda, who has a chance to reach No. 2 in the women's world ranking with a victory, fell back early with a double bogey by going long of the green on the par-3 fourth. She recovered with three birdies over the next five holes, and then really turned it on.

"Kind of hit the brakes every single day on the back nine," Korda said. "I told myself to be really aggressive on the back nine, and it worked out today."

She opened with three straight birdies, holing out from a greenside bunker on No. 11, and she was back in the game. Korda shot a 31 on the back nine for a 66.

Kim was at 16-under 200 and will be in the final group with Korda.

Caroline Masson of Germany, who will join them in the final pairing, had a 70 and was four shots behind, with Charley Hull of England another shot behind after a 66.

For so many others, an ideal day for scoring at Tiburon turned out to be a lost opportunity.

Brooke Henderson of Smiths Falls, Ont., who attracted the biggest gallery playing with Korda and with a horde of Canadians in Florida for the winter, had bogeys on three of the par 5s and never got anything going for a 71. She was six shots behind.

Hamilton's Alena Sharp is the only other Canadian in the field. She shot a 69 to sit in a tie for 24th at 5 under.

Defending champion Lexi Thompson made an early charge, only to be slowed by a pair of bogeys on the back — all her bogeys this week have been on the back nine — that gave her a 70 and put her seven shots behind.

Kim has shown few signs of coming back to the field. She has made only one bogey through 54 holes, and with her strong start it looked as though the 26-year-old Korean might run away from the field.

The back nine changed everything.

Korda appeared to be in trouble on No. 11 when she fanned a shot from the waste area into a bunker. She blasted it out and watched the ball crash into the pin and drop for birdie. She made another at the par-3 12th and took advantage at the end with a 4-hybrid on the green at the par-5 17th for at two-putt birdie.

Kim gave herself plenty of reasonable looks at birdie on the back nine. She couldn't get any to fall except for a 25-footer on the 15th hole that restored her lead to two shots, but only briefly.

Kim's second shot into the 17th was well short and to the right into a bunker, and she blasted out to some 30 feet away. She played away from the flag on the 18th and two-putted for par from about 40 feet.

Still, she was in the lead after the third straight day, one step closer to a massive payoff.

The format changed this year from a points-based system in which only the top 12 players had a shot at a $1 million bonus to any of the 60 players who made it to the Tour Championship getting $1.5 million in official money by winning the tournament.

Jin Young Ko, celebrated Thursday night as LPGA player of the year, tried to get back into the game with a 66. She still was six shots behind along with Jessica Korda (69), the older sister of Nelly Korda.

Ko is virtually a lock to win the Vare Trophy for the lowest scoring average and needs a 65 to become only the second woman to finish with a sub-69 average score for the year.

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