-LRB- CNN -RRB- -- American golfer Bill Haas said he was `` very lucky '' after securing the biggest win of his career on Sunday . The 29-year-old beat U.S Ryder Cup star Hunter Mahan on the third playoff hole at the Tour Championship in Atlanta to clinch the PGA 's season-ending FedEx Cup and $ 11.44 million in prize money . Haas needed a dramatic save after hitting a water hazard before going on to sink a four-foot putt on the par-three 18th hole at East Lake to finally see off his compatriot , after the duo had finished tied on eight under par through 72 holes . The dramatic triumph saw Haas -- whose father Jay played in the Ryder Cup on three occasions and won nine times on the PGA Tour -- leap from 25th in the FedEx Cup standings to claim the $ 10 million jackpot . He also pocketed $ 1.44 million for winning the Tour Championship , the final event in the four-tournament series , but said he was unaware of his double success until he stepped up to collect both trophies . `` I knew I was on the line , meaning the only way I could win in my position at the start of the week was to win the tournament , '' Haas told CNN . `` Even with that happening I still could not win the FedEx Cup because other people who were way ahead of me , their points would have passed me . `` So in my head , focus on one task -- and that was to win this playoff -- and whatever happens after that , happens . The chips fell my way and I 'm very lucky . '' It looked like Haas had blown his shot at glory when he hit a bogey and double bogey on the final two holes of Saturday 's third round to lose a share of the lead , but a 68 on Sunday allowed him to haul himself back up the leaderboard . It then looked as if nerves might get the better of Haas when the playoff began , as he hit a loose shot into the crowd on the first additional hole before finding the water on the second . But the new world number 20 found the green with a stunning shot to force a third playoff hole , where his par putt proved enough for victory . `` When I got up there I 'd heard the groans from the crowd , '' Haas said of the build-up to his incredible saving shot . `` I thought it was in the water , so I get up there and it is somewhat in the water . `` But it 's not fully submerged , so in my head I said to myself , ' I do have some sort of shot here . ' I hit the shot I thought I had to hit , and it came out perfect . '' Haas has also put himself in contention for the upcoming Presidents Cup clash between the U.S. and an International team starting on November 14 , with American captain Fred Couples due to announce his final wildcard pick on Tuesday . `` I 'm not going to say it gets me to Australia , '' Haas told the PGA Tour 's official website regarding the possibility of playing in the competition , which takes place in Melbourne . `` It definitely puts me in the talk up there with some of the guys that everybody has been talking about . '' Haas hopes to use this win as a springboard for the rest of his career as he looks to match some of the illustrious names who have previously clinched the FedEx Cup . `` It 's pretty sweet . You look at the names who have previously won this , I 'm trying to work my way to their stature and their level of play . This is just another stepping stone , I think I can get up there , '' he said . `` It 'll take a lot of work . Guys like Vijay -LRB- Singh -RRB- , Jim Furyk and Tiger Woods , obviously they 've put their time in , they 've put their work in and I need to do the same . I 've got to work hard to try and get better each and every year . '' Mahan thought he had the tournament sewn up after Haas ended up in the water , but the 29-year-old admitted Haas was in the ascendancy once his magnificent recovery shot fell close to the hole . `` I thought I had one on the second playoff hole and then he hits it out of the water to two feet , '' Mahan said . `` It seemed like he was destined to win this week . '' World number one Luke Donald knew a win at this event would be enough for him to claim the FedEx Cup , and in the process become the first man to top both the PGA and European Tour money lists . The Briton birdied three of the last five holes to finish one shot behind Haas and Mahan , in a three-way tie for third position along with South Korea 's K.J Choi and Australian Aaron Baddeley . `` I guess this is what the FedExCup is all about , '' said Donald , who would have claimed victory in the series if he had finished alone in third . `` It 's meant to be exciting . '' Australian Jason Day fell away in the final two holes of the final round after he hit two bogeys to slide from eight under to finish in a tie for sixth place alongside compatriot Adam Scott and American Charles Howell III . `` Obviously I 'm a little disappointed that I bogeyed the last two holes , '' Day , 23 , said . `` But I was trying to win out there . ''