SYDNEY, AUSTRALIA - MAY 26: Tim Cahill of the Socceroos competes for the ball in the air with Thulani Caleb Serero of South Africa during the International Friendly match between the Australian Socceroos and South Africa at ANZ Stadium on May 26, 2014 in Sydney, Australia. (Photo by Mark Metcalfe/Getty Images)

Sydney - Australia showed few signs they might buck their underdog status at the World Cup when they struggled to a tepid 1-1 draw in an international friendly against an under-strength South Africa on Monday.

More than 50 000 turned out at the Olympic Stadium to bid farewell to the Socceroos before they depart for the finals but the home side struggled to break down a Bafana Bafana team weakened even from that which went out in the second round of African qualifying.

Both the goals came inside a minute early in the first half with Ayanda Patosi's 13th minute effort for South Africa cancelled out by Australia's stand-in captain Tim Cahill almost immediately.

With world champions Spain, 2010 runners-up the Netherlands and Chile lying in wait in Brazil, Australia would have been hoping for a different conclusion to the evening than the slow handclap that rang around stadium towards the end of the match.

Socceroos coach Ange Postecoglou was always up against it with just eight months to bring fluency to his young team before Australia's third successive World Cup finals campaign and it showed in a ragged performance.

South Africa opened the scoring after Tokelo Rantie drove at the heart of the defence at pace and, when his progress was stopped, stabbed the ball back for Ayanda Patosi to slide the ball into the net.

Australia's response was immediate and it was no surprise that it came from the head of Cahill, who rose above goalkeeper Senzo Meyiwa to steer Tommy Oar's ballooned cross into the net for his 32nd goal in his 68th appearance for his country.

South Africa grew in confidence and had the better of the second half with what rhythm Australia had mustered disrupted by the inevitable string of substitutions.

Postecoglou will cut three players from his 30-man provisional squad on Tuesday before the remainder fly to South America - one certain to be central defender Curtis Good, who has a hip injury.

Australia open their campaign in Brazil against Chile on June 13 in Cuiaba before playing the Netherlands on June 18 and Spain on June 23.