At the end there no hiding how pleased McIlroy was.
"It was great," he said. "It was not the start I wanted. Three down after four is very tough against anybody, but against Lee, who's one of the best in the world, I was just trying to get back to level at some point in the round.
"To turn one up was a bit of a bonus. I made a few birdies and definitely played well to win that one." He was six under for the 17 holes and Westwood three under.
McIlroy added: "Maybe there's a little extra intensity (at three down), but I think you just have to stay patient and chip away."
On being one game away from possibly reaching World Number One for the first time he said: "It's very exciting. After Luke departed early (in the first round to Ernie Els) that was the goal, to give myself a chance."
Westwood said: "Rory played well. I think we both played well - it was just one of those typical match play games that went a lot with momentum."
He felt he was unlucky on the fifth when he flew the green and considered McIlroy even more fortunate at the long 11th, where the Ulsterman's wild second shot was heading for desert and possibly out of bounds, but hit a cart path and finished on grass near the green. It was halved in birdies.
"That sort of thing can change a match. Go back to level there it's a different kettle of fish. I thought it was big turning point.
"But I'm playing great. I've shot four or five under every day and that's pretty good golf. He can't let a game of match play with all its fickleness get in the way of when you are playing well.
"You build up your confidence and carry that forward."
He still had another game to play too. The event includes a third place play-off and there was a lot of money and loads of Ryder Cup points to play for against Wilson.
Winning the final was worth €1,060,767, while there was €644,037 for second, €454,614 for third and €371,268 for fourth.
McIlroy missed a golden opportunity to take the first, missing a four foot par putt after Mahan had already bogeyed, and the second was then shared in birdie fours.
It was a curious start to the final. The second and third were halved in birdies, but the first and fourth in bogeys. McIlroy had to take a penalty drop on the last of those after his drive kicked off a spectator into an unplayable bush, but Mahan failed to get up and down from a bunker and let him off the hook.
The curiosity included the American backing off his short par putt as an umbrella was caught by the wind and flew away from one of the hospitality units.
A deflated-looking Westwood, meanwhile, was two down to Wilson after six.