Colsaerts was set to face Graeme McDowell in the final after the Northern Irish Ryder Cup hero overcame home favourite Rafael Cabrera-Bello.
“It was a very intense game,” said last year’s semi-finalist Colsaerts. “I gave away a lot of holes too easily to Paul early on.
“Four down after four holes, and he made one mistake, he opened the door a little bit and I started to play good at that time. I lost 16 after getting back to all square, and you start to go ‘I'm running out of holes’. 18 obviously plays a little bit in my favour, I can get to the green in two.
“I didn't really feel that much pressure because I was four down all day and I was starting to play good towards the end, and I could see that Paul was not very happy - he wanted the match to finish a little earlier.
“I was probably feeling a lot better than he did, and I thought I was going to capitalise on that.
“I played well here and I probably deserved a place in the final last year, got one now, so I’m very excited.”
McDowell could hardly complain about his putting at the start of the final.
He made an 18 footer on the first and holed from nine at the next, but both were to keep him level as he missed both greens.
The pair met in the quarter-finals last year, with Colsaerts winning 2 and 1 - and he struck first with a 25 foot eagle putt on the long third after McDowell almost drove into the lake.
Colsaerts gave away his early advantage by driving into the lake on the fourth and double-bogeying.
He should have gone back in front on the next, but missed a three-foot birdie putt after McDowell had holed from further away for his par five.
Colsaerts made amends with a five foot birdie putt to win the sixth, bogeyed the next, but then went ahead for the third time after McDowell drove into the bushes and had to take a penalty drop.