Three bogeys in what turned out to be the second and final round of the Challenge Tour's Hainan Open in China proved costly for South Australian Nick Cullen.

With heavy rains plaguing the tournament from day one, the result was eventually declared after 36 holes, Cullen's second round of 1-over 73 dropping him more than 20 places down the leaderboard.

The likeable left hander opened with a credible even par round despite several stoppages in play and was inside the top-25 when 18 holes were eventually completed.

But back to back bogeys to open his second round had Cullen on the back foot and while he fought back bravely after making the turn 2-over eventually signed for a 73.

The T49 finish saw him slip to 51st on the season long Road to Oman standings with two events remaining to climb into the top-45 and qualify for the Tour's Grand Final in Oman in November.

The Tour remains in China for the Foshan Open next week then moves to the United Arab Emirates for the penultimate event of the season, Ras Al Khaimah 2016 Golf Challenge.

ullen was one of three Australasians in the field, fellow Australian Daniel Gaunt finishing a shot further back and T58 while New Zealand's Ryan Fox battled in the conditions to be 5-over after 36 holes and miss the cut.

The result saw Fox slip from third to fourth on the Road to Oman standings and while he is guaranteed status on the European Tour next year will be desperate to claim the number one spot and the added benefit of a full exemption.

He trails leader Jordan Smith by a little less than €40,000 and will need to play his best over the final three tournaments if he is to topple the Englishman.