Graeme McDowell ended one of his worst years with one of his best shots. Fortunate to even get into a playoff, McDowell ended it quickly with a 5-iron that grazed the edge of the cup on the 18th hole and settled 3 feet away for a birdie to win the OHL Classic at Mayakoba Monday. "I hit as good of a 5-iron as I could hit," McDowell said. McDowell closed with a 5-under 66 to finish at 18-under 266, and he had to make an 8-foot par putt on the final hole for that. It still looked as if it would only be good enough for second place when Russell Knox had a one-shot lead going to the 18th hole at El Camaleon Golf Club. Knox pulled his tee shot into a bunker, came up just short of the green and his chip-and-run came up was 12 feet short. He missed the par putt and had a 66, to join McDowell and Jason Bohn in a playoff. Bohn made tough par putts on four of his last five holes for a 68. The playoff in the rain-delayed tournament didn't last long. McDowell hit 3-wood off the tee and his caddie, Ken Comboy, talked him into a 5-iron. It was so pure that it looked as if it might go in. Knox missed the green to the left, while Bohn missed an 18-foot birdie putt. "You go through a year like this, you think, 'Am I finished? Am I not good enough?' You ask yourself all the questions," McDowell said. "It's the game of golf, and it's very difficult. I've been dreaming of this day and I said that I was going to appreciate it when it came. So I'm going to appreciate this one, because this year has been a grind." It showed at the end. McDowell and Knox were tied at 19 under when they returned Monday to complete the final round. Knox birdied the par-5 13th to pull ahead, only to drop a shot on the 14th to fall back into a tie. McDowell was well short on a 12-foot birdie putt for the lead on the par-3 15th, and then he came up 10 feet short on a 45-foot birdie attempt on the next hole. He missed that next putt and made bogey to fall one shot behind, and it looked as though he wouldn't get another chance. Knox was coming off his first win last week in Shanghai at the HSBC Champions, and was poised to make it two in a row. He stayed one shot ahead with a 5-foot par putt on the 17th, only to make bogey on the final hole. Derek Fathauer, the 54-hole leader, birdied the last hole for a 71 to finish two shots behind. McDowell wasn't planning on playing in Mexico except for his poor year. The 2010 US Open champion and Ryder Cup star had not finished in the top 10 in nine months dating to the Dubai Desert Classic. Instead of finishing the Race to Dubai on the European Tour, he chose to skip the final two events. The idea was to put 2015 behind him and get an early start on the new PGA Tour season. He attributed his slump to adjusting to life at home. His daughter, Vale, was born in September 2014 and McDowell said golf was no longer front and center. "It's been a rough year for all the right reasons," he said. "I've been enjoying life off the golf course with my beautiful family. Golf hasn't been the priority it should be. But the last three or four months I got back to where I want to be." — AP