Three weeks after putting his FedExCup play-off hopes on the back burner to perform best man duties at his brother's wedding, Zach Johnson emerged as the best man standing at the weather-delayed BMW Championship. Clutch birdie putts at the 16th and 17th helped him close with a superb six-under-par 65 to clinch his 10th PGA Tour title by two shots. It also lifted him to fourth in the FedExCup points standings heading into the season-ending Tour Championship this week in Atlanta, where he can secure the eye-popping play-off bonus of US$10 million with victory. All of this came after Johnson opted to miss the opening play-off event of the four-tournament series, The Barclays in New Jersey, due to a long-standing promise to support his brother Gabe at his wedding. "You're not going to miss your brother's wedding, especially when you're the best man," a smiling Johnson said. "I had zero intentions of missing that wedding, especially if I'm going to get along with my new sister-in-law. "But I planned for that. I scheduled accordingly. I played the Wyndham, which is a tremendous event, kind of an awkward date but a tremendous event." Johnson tied for fifth at the Wyndham Championship, then finished joint 27th at the Deutsche Bank Championship in Boston two weeks later, sinking a 7.5m birdie putt on his final hole to earn a place on the United States Presidents Cup team. "Big picture, it's been a nice three weeks," said the 37-year-old American. "Going into Boston, even though I had a week off, I felt good about it. I had one bad round in Boston. Technically a bad four-hole stretch that just took me out of it. "When it comes to that putt ... my last hole at Boston, you know, I had zero indication as to what it meant. I was just playing. I think that's what I've got to keep doing. "It's hard to grasp the last two weeks of golf because I was trying to make that Presidents Cup team without trying to make it. I was trying to get in the [FedExCup] top 30 this week without trying to make it." Johnson, whose only major win came at the 2007 Masters, had not played at Conway Farms as a professional and decided to visit the par-71 course on a scouting trip last month with his father and his brother. That helped pave the way for his 10th PGA Tour win, an achievement even he found humbling given the extraordinary depth in the modern game. "It's extremely difficult [to win]," Johnson said. "I'm not so sure I fully grasp it. The depth and the parity we have on this tour, in the world, in the sport, is second to none. "It's just extremely difficult because everybody is playing at a high level, and there's so many incentives to work and get better. I certainly take pride in the fact that I've done what I've done."