Australia toppled defending champions South Africa 19-14 in a thrilling final at Twickenham to win the London Sevens on Sunday and claim their first victory on the IRB Sevens World Series since Brisbane in 2002.

New skipper James Stannard raced the length of the Twickenham pitch in the dying seconds of the decider to make a match-winning tackle which secured Australia a memorable victory at the home of rugby in front of more than 40,000 fans.

Australia took an early lead in the Cup final when a brilliant try to Brackin-Karauria Henry in the fifth minute opened their account before South Africa drew level through a converted chip-and-chase effort from Fabian Juries.

Stannard broke the South African defence two minutes after halftime and crashed over for his fifth try of the tournament to swing the match back in Australia's favour.

The defending champions hit back again through Juries to regain a 14-12 advantage before forward Henry Vanderglas swooped on a chance offload to power over for a 19-14 Australia lead.

Cecil Afrika then looked certain to snatch South Africa a famous victory but Stannard cut him down with a spectacular match-winning tackle which cleaned up the corner post.

Australian coach Michael O'Connor said he was sure South Africa were going to sneak home right on the siren.

"An unbelievable tackle," O'Connor said.

"I thought James had no chance of getting him. I have no idea where he pulled that pace from. He's got to be the player of the tournament.

"The boys are absolutely thrilled. I am incredibly proud of them."

Stannard was also crowed highest pointscorer at the penultimate leg of the IRB Series with 67 points, while teammate Clinton Sills announced his return to the circuit with nine tries.

Australia's undefeated performance at the London Sevens moved them into equal third with Fiji behind Samoa and New Zealand on the overall standings.

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