ATLANTA — Scottie Scheffler returned to East Lake on Sunday morning looking every bit like the world’s No. 1 player, pulling away with four birdies over six holes to complete the third round with a 4-under 66 that gave him a 6-shot lead in the Tour Championship.

Scheffler was delivering a steady diet of pars that put him in a tight battle with Xander Schauffele until a second stoppage due to lightning in the area Saturday. At the time, Scheffler was 1 shot ahead.

And then he was gone.

Scheffler holed birdie putts from about 5 feet on the 13th and 15th holes. He stuffed his approach to 2 feet on the 17th and then made a superb escape from the left rough over the water that left him a long pitch he nearly holed on the par-5 18th.

He tapped in to reach 23-under par. That put him one round away from the $18 million prize for winning the FedEx Cup.

Rory McIlroy birdied his final two holes for a 63 and will be in the final group with Scheffler. He was at 17 under along with Schauffele, who had good looks for birdie but didn’t make any of them Sunday morning.

Defending champion Patrick Cantlay (66) and Sungjae Im (66) were 7 shots behind.

Scheffler is the No. 1 seed in the FedEx Cup and was rewarded with a 2-shot lead at 10-under par before the tournament started. He is 13 under for his raw score, which is tied for McIlroy for the best this week. McIlroy, however, was the No. 7 seed and began 6 shots behind.

Schauffele missed an 8-foot birdie putt on the 13th hole when they resumed the round. He sent his next tee shot so far to the right that he had to hit a provisional in case it was out of bounds. He found the ball but wound up missing a 10-foot par putt to fall 3 behind.

On the par-3 15th, Scheffler hit his tee shot to 5 feet to a front left pin over the water. Schauffele also hit a good one to 10 feet and missed again.

Scheffler already has won four times this year, including the Masters, to reach No. 1 in the world and is considered a shoo-in for PGA Tour player of the year.

He won just over $14 million in the regular season — already a record, and not surprising given the steady rise in prize money. He won a $4 million bonus from the “Comcast Business Tour Top 10” for leading the FedEx Cup in the regular season, along with a $1 million bonus for winning the Aon Risk-Reward Challenge.

A victory Sunday afternoon would equate to a $37 million year for the 26-year-old Texas grad.