ATLANTA — Justin Thomas took a step toward winning the FedExCup and its $10 million bonus when he jumped into a share of the second-round lead at the Tour Championship on Friday.

The powerful Thomas eagled the par-five 18th after hoisting a five-iron to five feet for a four-under-par 66 on another benign day at East Lake in Atlanta.

He warned the best was yet to come.

“I’ve hit a lot of good putts which have just caught the edge. Hopefully the putter can heat up and we can have some fun this weekend,” Thomas told Golf Channel after joining fellow American Webb Simpson and Englishman Paul Casey at seven-under 133.

Jordan Spieth struggled with his long game and only a sublime touch around and on the greens allowed him to limit the damage to a 70 that left him four shots behind.

Spieth leads the season-long FedExCup standings, ahead of second-placed Thomas.

A victory by either on Sunday would clinch the season-long FedExCup and the $10 million bonus, and Thomas for now is in a happier spot.

The PGA Championship winner played mixed power and precision but until the final hole had not extracted full value from his round.

But one brilliant swing from 235 yards changed that.

“I absolutely crushed it. It was about as much as I can get out of a five-iron,” he said, before adding that he was trying to keep thoughts of the FedExCup out of his mind.

“All I’m trying to do is just pick apart the golf course and pick my spots, and just hit the fairways.

“If I drive the ball like I did yesterday and some of the holes today you can really make some birdies out here. I really haven’t made (many putts).”

Simpson and Casey both shot 67, with a double-bogey at the 13th after a poor drive taking the wind out of Simpson’s sails.

However, things could have been worse for the 2012 U.S. Open champion, whose drive at the previous hole landed on the top of the out-of-bounds fence and took a fortuitous ricochet back into play, from where he made par.

Thomas, Simpson and Casey lead by one stroke from a group of four including American Patrick Reed, whose 65 was the day’s best score.

First-round leader Kyle Stanley set the tone for a frustrating day by lipping out a par putt at the first hole en route to a 73 that left him four shots behind. — Reuters