But for all the great shots, the match ended when Mahan went from a tough lie in the bunker to a bush in the desert, and it took him four shots to reach the 17th green. Kuchar wound up winning, 2 and 1, when Mahan removed the stocking cap he used to fight the cold desert air and conceded Kuchar a short birdie putt.
It was the first World Golf Championship title for Kuchar, and it follows a year in which he won The Players Championship. Kuchar became the second player in the last three years to win the Match Play Championship without ever playing the 18th hole.
"It seems like each hole there's so much momentum riding and so much pressure on every hole," Kuchar said. "To come out on top after six matches of playing the top 64 guys in the world, it's an incredible feeling."
Mahan was trying to join Tiger Woods as the only back-to-back winners, and he gave it a good shot despite the big deficit halfway through.
"Just had a bad stretch against Matt on the front nine there that put me just a little bit too far behind," Mahan said.
In a strong, cold wind the wind chill index reached a low of 37 degrees Mahan made a long two-putt par to win the 10th, and played a tough chip from the mound of a bunker to about 6 feet for a birdie on the next hole.
Mahan followed with a tee shot into about 10 feet on the par-3 12th, the momentum squarely on his side. Kuchar, however, followed with an 8-iron to just inside 15 feet and made the birdie putt.
"The shot was certainly good, but the putt was really crucial, and when that went in, I felt like I was still in control of the match," Kuchar said. "Had that putt not gone in, it would have been only a 1-up lead, and I think the match was in anybody's hands at that point."
Inbee Park of South Korea took advantage of Ariya Jutanugarn's triple bogey on the last hole to secure a one-stroke victory in the LPGA Thailand in Chonburi.
Jutanugarn blew a two-stroke lead on the 18th when she first had to take a drop and then missed a three-foot putt to force a playoff. The 17-year-old Thai golfer, who had a hole-in-one earlier in the round, was moved to tears as the putt lipped out, while a surprised Park started celebrating in the clubhouse.
Storylines A first for Kuchar
R Matt Kuchar tops Hunter Mahan in the final, winning his first World Golf Championship title.
• Mahan, who had gone 169 holes without trailing in the tournament, falls behind after the fourth hole and never catches up.
• Kuchar won 2 and 1 on the 17th hole.