The defending champion, Bo Van Pelt of the United States sees through his stroke during the first round of the ISPS HANDA Perth International golf tournament in Perth, Australia, on Oct. 17, 2013. (Xinhua/Zhou Dan)

 The defending champion, Bo Van Pelt of the United States sees through his stroke during the first round of the ISPS HANDA Perth International golf tournament in Perth, Australia, on Oct. 17, 2013. (Xinhua/Zhou Dan)

Dustin Johnson of the United States makes a shot during the first round of the ISPS HANDA Perth International golf tournament in Perth, Australia, on Oct. 17, 2013. (Xinhua/Zhou Dan)

Brett Rumford of Australia sees through his stroke during the first round of the ISPS HANDA Perth International golf tournament in Perth, Australia, on Oct. 17, 2013. (Xinhua/Zhou Dan)

The defending champion, Bo Van Pelt (L, front) of the United States talks with his compatriot Dustin Johnson (R, front) during the first round of the ISPS HANDA Perth International golf tournament in Perth, Australia, on Oct. 17, 2013. (Xinhua/Zhou Dan)

The defending champion, Bo Van Pelt of the United States reacts during the first round of the ISPS HANDA Perth International golf tournament in Perth, Australia, on Oct. 17, 2013. (Xinhua/Zhou Dan)

Dustin Johnson of the United States makes a shot during the first round of the ISPS HANDA Perth International golf tournament in Perth, Australia, on Oct. 17, 2013. (Xinhua/Zhou Dan)