Kuchar won 2&1 but at one stage lead by four before a great fight-back by Mahan but the task always appeared a bridge too far after the winner had moved four clear through nine holes.
Mahan won the 10th, 11th, 14th and 16th holes but lost the 13th and the 17th to eventually lose the match at that hole.
Afterwards Kuchar was almost overcome with what he had just achieved. "I'm not sure I can explain how excited I am to have won this tournament. Match play I find to be such an amazing, unique format, so much fun to play and so much pressure. It seems like each hole there's so much momentum riding and so much pressure on every hole. To come out on top after six matches of playing guys, the top 64 guys in the world, it's an incredible feeling."
Kuchar reflected on his return to the elite of the game after a period in the mid 2000's where he was a long way from the golfer he is now.
"I've really got to say the credit would be in finding an instructor, Chris O'Connell. He really helped rebuild my game. That was in 2006, I found my way back on the Nationwide Tour, got introduced to Chris O'Connell, we started working, and he's turned me into the golfer I am today. I mean, just my work with him, I've become so much more consistent of a player.
"I was good in my younger days but streaky. I could be really good for a while and then struggle. And now I feel like I'm a golfer that can hit quality shots week in and week out, day in and day out. So I owe a lot of credit to Chris O'Connell.
In all of those matches this week Kuchar never once reached the 18th hole except in a practice round.
It is hard to believe that Matt Kuchar is only the number 23 ranked player in the world. He won't be for long as when the new rankings come out later today he will be inside the top ten and given his remarkable consistency over the past two years he deserves to be. His rise is not likely to stop there.
A special mention of the effort by Mahan who despite an unassailable deficit fought valiantly to try and retain his Accenture crown. It was not to be but his was a brave effort having beaten Matteo Manassero, Richard Sterne, Martin Kaymer, Webb Simpson and Ian Poulter to reach the final.