Australia's match racers have lost the first race of their gold medal decider at the Olympic sailing regatta.

The Australian crew - Olivia Price, Lucinda Whitty and Nina Curtis - are competing against Spain in a best-of-five final in Weymouth Bay.

Spain easily won the first race, crossing the finish line about five metres ahead of the Australians.

The match racing crew are hoping to win Australia's fourth gold medal at the Olympic regatta.

NZ Newswire