The 38-year-old American continued his stellar comeback from a tough period as he triumphed in The Sentry with a winning score of 29-under on the Plantation course at Kapalua, Hawaii.

Sahith Theegala was hot on his countryman’s heels carding a blistering 10-under 63, with five birdies on each nine, but had to settle for second place, one shot ahead of former champion Jordan Spieth (65) after a hectic final day shootout.

Former World No.1 Day was challenging for the lead after four birdies in his first seven holes before a wayward tee shot at the 8th led to a double bogey which derailed his bid for a 14th PGA Tour win. He signed for a 67 and tied for 10th.

Kirk made eight birdies in his final round and earned $3.6 million (A5.35m) from the $US20 million purse for the first of eight signature events in the new PGA Tour model of large purses and elite fields.

"I'm enjoying competing, I'm enjoying the work. I didn't have that for a while. It's a constant process and I'm just loving every minute of it." – Chris Kirk.

It was his sixth tour victory but his greatest win remains his recovery from alcoholism and depression, which led to him stepping away for six months of treatment in 2019.

He won the Honda Classic last year, and the PGA Tour honoured him with its "Courage Award" at the end of the season.

This victory assures him a spot in the Masters – he was just outside the top-50 in the world at the end of 2023 – and allows him to book a return trip to Kapalua to start next year.

He was making his first appearance at The Sentry in eight years.

"I'm so thankful for these last five years. It's been incredible," Kirk said.

"I'm enjoying competing, I'm enjoying the work. I didn't have that for a while. It's a constant process and I'm just loving every minute of it."

Kirk's winning score was still five shots shy of the tournament record 34-under Australia's Cameron Smith produced when winning the event – then known as the Tournament of Champions – on the same course in 2022.

Sungjae Im made the PGA Tour record books with 34 birdies this week as he tied for fifth at 26-under. The previous best for 72 holes was 32, set three times, most recently in the same event last year by eventual winner Jon Rahm.