Paul took a share of the lead into the final round at Son Muntaner Golf Club, but covered his first 15 holes in two over par to fall two shots behind England's Marcus Armitage.
However, Armitage then three-putted the 16th and sliced his tee shot out of bounds on the next, where Paul's hooked drive almost suffered the same fate but finished up against a stone wall.
Paul was able to take a free drop due to standing on an adjacent cart path and made par, while Armitage ran up a double-bogey seven and also bogeyed the last.
With Paul Waring and Nicolai von Dellingshausen in the clubhouse on 14 under par a play-off looked on the cards, but Paul holed from 15 feet on the last to secure the win with a closing 72, 10 shots more than he needed in round three.
"It was tough today," Paul told Sky Sports.
"My ball-striking was unbelievable all week. I hit it really close the first couple of holes and couldn't make any putts so that was really hard to stay in the moment.
"But luckily none of the other guys really made a lot of putts so I saw after nine holes I was in the lead and I thought I hit a great shot on 15 but it went over the green.
"From there you have no shot and Marcus holed a great putt (for birdie) so then I was two shots behind. Unfortunately Marcus hit a couple of bad shots and then I couldn't have dreamed of a better ending. I'm over the moon.
"I had a lot of good chances the last couple of days that didn't go in and to finish like this is obviously a dream come true."
Waring had set the clubhouse target thanks to a closing 66, the lowest score of the day, with Von Dellingshausen matching his total thanks to a birdie on the 18th.
Overnight joint-leader Ryan Fox and England's Dale Whitnell shared fourth place on 13 under, with Armitage's poor finish dropping him into a tie for sixth with defending champion Jeff Winther and Jazz Janewattananond.