Cameron John was the leading Australian but fell down the leaderboard to a share of 20th place, having started the day four shots off the lead.

With the tournament reduced to 54 holes after Thursday's washout, Mansell went into the third and final round one shot off the lead on 10-under-par but soon hit the front courtesy of five birdies in a row from the 4th hole.

The two-shot lead he held at the turn had gone by the time he reached the 18th tee but he saved his best until last, two-putting from long range to end his wait for a first title at this level.

His closing six-under 66 left him at 16-under, one shot ahead of Japan's Keita Nakajima, with Northern Ireland's Tom McKibbin and Frenchman Adrien Saddier another stroke further back. 

John carded a two-under 70 to finish nine-under, seven shots off the pace.

He was four-under for the day - 11-under for the tournament - after five birdies and no bogeys between holes 3 and 13, but after a bogey at 15 and a birdie at 16, he bogeyed his last two holes.

Mansell's first visit to the winner's circle came in David Kenny's first week on his bag and the 29-year-old was full of praise for him. 

"What a feeling. Just to get into that position, and I played so well today," he said.

"First week with a new caddie so that was a good start and he just, a couple of times, got me to slow down. 

"And it makes those near-misses and when I've got ahead of myself in the past just kind of worth it and it just means that much more. 

"One thing I'd say to people trying to do it as a career, that moment's the most fulfilling thing in the world and it's worth it. 

"So stick in and hopefully you'll get rewarded one day like I have today."