Jason Day made a 7-foot par-saving putt on the 16th hole, Thomas Bjorn bogeyed and the Australian won his first tournament in nearly three years at the World Cup at Royal Melbourne.
Day's closing 70 left him with a 10-under 274, two strokes ahead of Bjorn with a 71.
Adam Scott finished third after a 66, three strokes behind.
Scott, trying to win his third tournament in a row, shot 75 on the opening day, including a nine on the 12th hole, and spent the rest of the tournament trying to catch up.
Day won $1.2 million and Australia won the team portion of the World Cup as Day and Scott, who each holed approach shots for eagles Sunday, also shared the $600,000 first-place prize.