CROMWELL, Conn. -- It's not often a PGA Tour winner starts his round before noon on Sunday. So when Marc Leishman teed it up at 11:50 a.m. ET, not many gave the Aussie a shot at a Travelers Championship victory.

That changed quickly as the 2009 PGA Tour Rookie of the Year went out in 30 and finished with an 8-under-par 62. Part of his inspiration? As he was getting ready to play his last 18 holes, Leishman crossed paths with Hunter Mahan, who just finished shooting a 9-under 61 in the first group out on Sunday.

But starting his day, did Leishman legitimately think he had a shot to win?

"Waking up this morning [6 shots back], I definitely didn't think I was going to be in this situation, but I'll gladly take it," said Leishman, who played the eight par-5s at 8 under for the week and won by a shot. "It's an unbelievable feeling. It's probably not the way I would have expected to get my first win. But what do you say, you take them when you get them, any way you can."

Throughout the afternoon, many of Leishman's challengers fell by the wayside, chief among them Charley Hoffman. Leishman, 28, walked off the TPC River Highlands course at 3:39 p.m. ET at 14 under as the co-leader with Hoffman, who still had seven holes to play.

Hoffman pulled 2 shots ahead with a 2-putt birdie at the par-5 13th hole, and appeared headed for a third victory until his tee shot on the 17th hole found the water down the right side of the fairway. After making a double-bogey 6 that dropped him into a tie for the lead with Leishman, Hoffman bogeyed No. 18 to fall out of a potential playoff.

"What I did on 18 was pretty pathetic," Hoffman said. "Fanned [my drive] out to the right, and pretty poor second shot, pretty poor bunker shot and even worse putt. So when it's said and done, obviously a bad finish and bad taste in my mouth. But you learn from it."

Another potential spoiler to Leishman's victory party was 54-hole co-leader Roland Thatcher. After struggling early in his final round, Thatcher flipped the switch by draining a 14-foot putt for eagle that got him back in the mix. A hole later, though, Thatcher one-hopped his tee shot on the drivable par-4 15th into a pond, seemingly ending his hopes at a first PGA Tour victory.

Then after a par at No. 16, Thatcher made an impressive birdie at the par-4 17th hole. That set up No. 18 where Thatcher knew he needed a birdie to force a playoff.

"I just gotta tell you, [with the] ball in the air on 18, I thought it was close," Thatcher said after his approach shot from the fairway missed the putting surface by just a few feet and found a greenside bunker. "I was staring it down. I really did think it was going to end up tight, but it just didn't quite end up carrying enough and that's not a really good spot to leave it."

Bubba Watson, the 2010 Travelers Championship winner who has been trying to find his game since his Masters victory in April, made a charge early in the final round, but a long birdie putt on the last hole that would have gotten him into a playoff with Leishman went just wide of the cup. Watson said he won't be back on tour until the British Open in mid-July.

Amazingly Leishman's bogey-free 62 isn't the low final round by a winner in the 60-year history of the Travelers Championship. Both Scott Verplank (2001) and Brad Faxon (2005) shot 61s. Leishman's 62, though, does tie his career-low round on the PGA Tour, which he also shot in Round 2 of the Deutsche Bank Championship in 2009.

At the start of the day, 19 golfers stood ahead of Leishman on the leaderboard. He teed off in the 14th-to-last pairing. And after all was said and done, he's the one with the perma-grin that could be seen all the way to Oz.

Kevin Maguire is the senior golf editor for ESPN.com. He can be contacted at Kevin.Maguire@espn.com.