One horror hole has severely endangered Adam Scott's winning streak but fellow Australian Jason Day is within two shots of the lead after round one of the World Cup.
Denmark's Thomas Bjorn and American Kevin Streelman lead the tournament at Royal Melbourne after each shot 5-under-par rounds of 66 on Thursday.
Their two nations also lead the team event, after their respective partners, Dane Thorbjorn Olesen and American Matt Kuchar, each shot even-par to make team totals of 5-under.
Scott, coming off wins in the Australian PGA and Masters, carded a 4-over 75, including a quintuple-bogey when he used three balls off the tee thanks to a mental lapse on the par-4 12th.
Day, dealing with the grief of losing eight relatives in Typhoon Haiyan, shot 68.
While that left the 26-year-old well-poised in the individual event, he and Scott's 1-over total leaves them six shots adrift as they try to win the World Cup for Australia for the first time since 1989.
His second went deep into a thick grove of trees and he was unable to play that either.
Even that found the rough, his sixth went over the green and he needed a chip and two more putts to complete the horror hole.
"Just a couple of lazy swings today on 12 and I paid the price," Scott told reporters.
But he hasn't ruled out a comeback victory, saying with Royal Melbourne's greens getting faster it might not take any spectacular low rounds to rein in the leaders.
"If I can plug away at it I'll maybe claw my way back into it," Scott said.