Australia made a fantastic start, with Russell Ford scoring twice in the first ten minutes.
A third goal from Mark Knowles at the start of the second half made the score 3-0 and looked to have put the game beyond Team GB.
Jonathan Clarke hit back for the British on 46 minutes for what seemed just a consolation effort.
A late rally from Team GB earned them a memorable and unlikely draw. Barry Middleton had the home fans dreaming when he converted a penalty corner to make it 3-2.
With just minutes left on the clock James Tindall scored a brilliant equaliser, which counted, despite Australian protests.
A remarkable match ended 3-3 and left the sides level at the top of Group A.
Great Britain now need to beat Spain on Thursday to guarantee a place in the semi-finals of the men's hockey tournament.