What happened to the Australian soldiers at Kokoda?

They fought in exhausting and debilitating conditions. Originally outnumbered by the small Japanese force, and pushed into withdrawal down the track, they were reinforced and drove the Japanese, who were running low on food and ammunition, back up the Track through Papua and into New Guinea.

To oversimplify greatly, the Australians and Papuans were at first beaten back by the Japanese. Eventually, as the Australians were reinforced and the exhausted Japanese were not, the situation was reversed and eventually the lost ground was recovered.http://www.ww2australia.gov.au/asfaras/kokoda.html