Jordan Spieth keeps nerve to win Oz Open after three-man playoff

World number three Jordan Spieth kept his nerve to win the Australian Open for the second time after triumphing in a three-way playoff on a tense final day on Sunday.

The American golfer sank a three-metre putt for birdie on the 18th hole to beat out Aussies Cameron Smith and Ash Hall in a thrilling finish at the Royal Sydney Golf Club.

Jubilant with the victory, Spieth said, "I felt like I really closed well on this last hole. I'm going to take that going forward."

"I love it here, we love coming back here. It's a challenging golf course, very different golf course, but we embrace the challenge. We got in early, were out here Sunday a week ago, really trying to learn what we can about a new place and had a great time in the process as well," he was quoted as saying by news.com.au.

Overnight leader Geoff Ogilvy held the lead going onto the 16th hole but a wayward drive into the trees saw him take a horror double-bogey and end his chances for victory.

Australia's Adam Scott finished off the pace in equal 14th, after making a 73.