NORTON, Mass. — The victories keep piling up for Justin Thomas, and all that does is make him want more.

In a Labor Day finish that was harder than the final margin suggested, Thomas kept his patience when Jordan Spieth shot out to a brief lead and Marc Leishman built a two-shot lead at the turn. Keeping his mistakes to a minimum, Thomas outlasted them both by closing with a 5-under 66 for a three-shot victory in the Dell Technologies Championship.

He started the PGA Tour season last fall at No. 34 in the world, with only one career win.

Now he has five wins this season, including his first major three weeks ago at the PGA Championship. He is up to No. 4 in the world, and barring Spieth running the table in the final two FedEx Cup playoff events, the 24-year-old Thomas seems a lock to be voted PGA Tour player of the year.

“I have two events left. I have two more opportunities to win,” Thomas said. “And I’d love to make it six or seven wins.”

Thomas made only two bogeys all week, the last one putting him in a three-way tie with seven holes to play. He won on the back nine at TPC Boston with a sand wedge he gouged out of the rough to 6 feet on No. 13, a gap wedge to 4 feet on No. 15 for another birdie, and a 6-foot par save that kept him two shots clear.

Spieth wasted a start that riled up the crowd – birdie-eagle-birdie-birdie – by missing the 14th green with a 5-iron for bogey. Needing an eagle on the par-5 18th, Spieth pushed a 4-iron into a tough lie in the bunker, blasted over the green and made bogey for a 67.

Spieth was runner-up for the second straight week. There wasn’t much he could have done to stop Thomas, his best friend in golf since they were teenagers.

“Came out firing, like I said we had to do,” Spieth said. “Eight through 14 is the meat of the golf course. You want to get through even. I got through over par and didn’t get any coming in when I hit some good putts.”

Spieth still moved to No. 1 in the FedEx Cup standings with one more event before the $10 million prize is decided at the Tour Championship.

Leishman shot 30 on the front to build a two-shot lead, but then made three straight bogeys and closed with two more bogeys.