Jon Rahm knew he was swinging well and finally got rewarded for it when he made five birdies and an eagle over his last 10 holes, giving him a 5-under 66 and a two-shot lead Saturday at the halfway point of the Dell Technologies Championship.
Rahm already has a short history of strong finishes in his first trip to the TPC Boston.
One day after he birdied four of his last five holes, he made a 12-foot eagle putt on the par-5 18th and then shot 31 on the front nine to reach 9-under 133.
No one could catch him in the afternoon, least of all Dustin Johnson.
Johnson, the world's No. 1 player who had a one-shot lead going into the second round, had a pair of double bogeys after a quick start and needed a birdie on the 18th hole to keep from falling further behind. Johnson shot a 72 and was five shots behind.
Paul Casey, who played in the final group last year until Rory McIlroy ran him down, had a 65 and was two shots off the lead along with Adam Hadwin (65), Kevin Streelman (65) and Kyle Stanley (68).
Streelman is at No. 90 in the FedEx Cup, and only the top 70 after the Labor Day finish advance to the third playoff event in two weeks outside Chicago.
Rahm was only part of a cool, calm day that left a large crowd entertained, and at times surprised.
Lucas Glover (No. 16) and Grayson Murray (No. 8) each made a hole-in-one that the PGA Tour estimated were 65 seconds apart. Phil Mickelson dropped only one shot on his way to a 67. He was just three shots off the lead at 6-under 136, his best 36-hole score since the FedEx St. Jude Classic in June. Jordan Spieth also turned around his fortunes. Despite missing a pair of birdies inside 7 feet, Spieth still shot a 65 and was in the group four shots behind.
McIlroy, meanwhile, was headed home after missing the cut as the defending champion for only the second time in his career. McIlroy also missed the cut as defending champion in the 2012 U.S. Open.
McIlroy will still advance to the BMW Championship, though he will need a top finish to get to East Lake for the Tour Championship.
That's no longer a concern for Rahm, the 22-year-old from Spain who is playing the FedEx Cup playoffs for the first time. His goal at the start of the year was to get to East Lake at the end of the playoffs and win a tournament.
He is No. 5 in the FedEx Cup, already assured of going the distance. He won at Torrey Pines in January. He even won his first European Tour title at the Irish Open. And he has soared to No. 5 in the world.
At some point, he began to wonder what else he had left to accomplish. Suddenly, there are 10 million reasons to start playing his best golf. As much as he has shown an affinity for the big stage against the best players, he is in reasonable position to allow himself to think about the $10 million bonus for winning the FedEx Cup.
He still has a long way ahead of him at the TPC Boston. Twenty players were within five shots of the lead with two rounds to go, and players were bracing for a Sunday of wet weather. The tee times were moved back and will be played in threesomes because of the forecast.
The cut was at 3-over 145, which spared the likes of Bubba Watson, who is at No. 72 in the standings. Watson missed a 3-foot par putt on the par-5 18th hole and figured he would miss the cut until Patrick Rodgers hit into the junk on the 18th hole, had to take a penalty drop and made bogey.
Adam Scott wasn't so fortunate. He came up short of the 18th with a sand wedge and missed a 6-foot par putt, giving him a 75. He wound up missing the cut by one shot after flying in from Australia to try to extend his season.