PHILADELPHIA (AFP) — Austrian Sepp Straka held off Ireland's Shane Lowry in an 18-hole duel to win the PGA Tour's Truist Championship at Philadelphia Cricket Club on Sunday.

Straka's two-under round of 68 earned him a two-stroke win over Lowry and Justin Thomas who shared second place.

Lowry was in contention until the final hole, which he went into just a stroke behind playing partner Straka, but he three-putted for bogey while Straka made par.

Straka, who moved from Austria to Georgia aged 14, secured his fourth career win on the PGA Tour and his second this season following his victory at The American Express.

Rory McIlroy is the only other player to have multiple wins on the PGA Tour so far this season.

The Truist was the sixth signature event of the season and Straka's win comes ahead of the season's second major, the PGA Championship at Quail Hollow which gets underway on Thursday.

Straka and Lowry went into Sunday's final round sharing the lead, but the burly Irishman quickly got ahead with a birdie on the par-four opening hole where he sank a 13-foot putt after a fine approach shot.

On the par-five fifth, Lowry made a birdie but Straka made an eagle, draining a 20-foot putt after finding the green from 220 yards out to tie the lead.

Straka bogeyed the next, but the momentum shift arrived on the par-three eighth, where the Austrian made birdie but Lowry missed a 10-footer and made bogey.

Straka reached the turn with a two-stroke advantage after a birdie on the ninth.

Again, the lead vanished quickly as Straka made successive bogeys to start the back nine and it was still neck and neck after both players made birdie on the 15th.

Lowry left a par putt just short on the par-three 16th to give a one-shot lead back to Straka, who this time held firm with pars on the final three holes.

Straka was delighted to secure victory in a signature event for the first time.

"It's huge, the biggest win of my career. Just so grateful for the process and the whole team that kind of makes me play as well as I do," the 32-year-old said.

"Every week, my coaches weren't here this week, but they're there almost every week. Even this week when they weren't here, there's always a back and forth, and they're always working on my game to help me succeed. It's great to see their hard work pay off," he said.

Thomas had fought his way into contention but was left to rue a missed six-footer which he left three feet short of the hole.

"It was a bad putt. It wasn't one that I obviously thought I would miss but I'm choosing to focus on all the other ones I made today rather than that one," he said.

Masters champion McIlroy finished tied for seventh, six shots behind Straka after a final round two-under 68.

The Northern Irishman accepted his driving accuracy had been off but was looking forward to competing for a second major of the season at Quail Hollow — where he has won four PGA Tour titles.

"Overall, I felt like I got a little better as the week went on," he said.

"Played well. I wish I'd made a few more birdies. I've got a better gauge of where my game is standing here right now than I did at the start of the week.”

"I wish I had gotten myself into contention a little bit more, but it was a good week, especially looking ahead to next week," he said.