MELBOURNE, AUSTRALIA - JANUARY 21: Eric Butorac of the United States and Raven Klaasen of South Africa in action in their fourth round doubles match against Treat Huey of the Philippines and Dominic Inglot of Great Britain during day nine of the 2014 Australian Open at Melbourne Park on January 21, 2014 in Melbourne, Australia. (Photo by Scott Barbour/Getty Images)

Johannesburg – South African tennis player Raven Klaasen and his American partner Eric Butorac on Tuesday advanced to the semi-finals of the men's doubles at the Australian Open in Melbourne.

Klaasen and Butorac narrowly defeated 12th seeds Filipino Treat Huey and Dominic Inglot of Great Britain 6-7 (3/7) 7-6 (8/6) 6-4.

The unseeded pair caused a major upset early in the week, knocking out top seeds and world number one pair, twin brothers Bob and Mike Bryan of the US 7-6 (11/9) 6-4 in round three.

They will meet the winners of the match between Australians Alex Bolt and Andrew Whittington and eighth seeds Daniel Nestor of Canada and Nenad Zimonjic from Serbia on Thursday.

The last South Africans to reach the semi-finals of the Australian Open doubles were the unseeded pair of Wesley Moodie and Jeff Coetzee in 2008. – Sapa