Leishman leapt from 14th into outright third at 12-under 268 at the Travelers Championship.

He was a shot behind American duo Harris English (65) and Kramer Hickok (67).

In a marathon eight-hole play-off duel for the title, English sunk the winning putt for birdie on the 18th hole.

The 31-year-old American became the only two-time winner on the PGA Tour this year after the equal second-longest sudden-death playoff in Tour history.

Former World No.1 Jason Day, who led at the half-way mark and played in the final round with English, carded a final round 70 to finish in a tie for 10th.

Cameron Smith, who sat alongside Day in third heading into the final round, had a disappointing 74 to drop to a tie for 30th.

Adam Scott signed for consecutive scores of 67 to finish in a group tied at 13th, Lucas Herbert's 69 on Sunday left him T-19th and Matt Jones (73) faded to 36th.

Leishman said that news earlier in the day of the death of his golf agent John Mascatello, who represented more than 30 players on the PGA Tour, had put the disappointment of missing the playoff into perspective.

"It was a tough day – one of our close friends passed away this morning – John Mascatello. I was definitely thinking about that and it made things a little ... golf is obviously not the be all end all."  Marc Leishman

"It was a tough day – one of our close friends passed away this morning – John Mascatello," Leishman said.

"I was definitely thinking about that and it made things a little ... golf is obviously not the be all end all.

"Not getting over the line, that's kind of irrelevant at the moment.

"I'm thinking of his family."

Leishman, who along with Smith will represent Australia at the Tokyo Olympics, opened with a birdie and then added a further three on the front nine to make his ascent on the leaderboard.

While he added two more on the 13th and 15th, the third required to level with the leaders proved elusive – after almost holing out from a bunker on the last

"It was nice to get off to a good start – I knew that I needed to have a really low one to have a chance," the World No.43 said.

"A birdie on 17, possibly 18, would've helped my chances a lot but I was happy with the day.

"My game is feeling really good and it was nice to make a run and be around the lead."