The two-time Masters winner demolished Kevin Kisner 7 and 6 in the final at Austin Country Club to earn his second PGA Tour victory of 2018, with the Masters one week away.

Watson was on course for a rare 10 and 8 victory when he won the first five holes, but fellow American Kisner prevented the humiliating result when he halved the par-5 6th hole.

Kisner won his only hole at the par-3 11th to keep the match on ice, but Watson closed out with a birdie at the par-5 12th.

"It's one of those things, I got off to a hot start and I was focussed on golf and committing to the shots," Watson said.

It is the left-hander's second WGC title, having claimed the 2014 WGC-HSBC Champions event in China.

Watson defeated Kevin Kisner 7 and 6 in the final of the WGC-Match Play to win the Walter Hagen Cup. PHOTO: Richard Heathcote/Getty Images.

An emotional Watson, who won the LA Open at Riviera Country Club in February, credited the support of his mother Molly, who was in the gallery for Watson's 11th career victory on the US Tour.

"Hugging my mum just now, she said I was good but I said without you I'm nothing," Watson said.

"Without my mum's upbringing, who knows where I'd be."

The 39-year-old Watson booked his place in the final with a 3 and 2 victory over Justin Thomas, who had the chance to usurp Dustin Johnson as World No.1 if he defeated Watson.

Kisner's run to the final was not as easy, going to an extra hole in his semi-final against Sweden's Alex Noren.

An out-of-sorts Thomas was then swept aside 5 and 3 in the third place play-off match.

- Evin Priest, Australian Associated Press