Novak Djokovic survived an almighty scare from an inspired Stan Wawrinka in a five-hour, five-set thriller at the Australian Open on Sunday, reaching a 15th consecutive grand slam quarter-final.
Berdych overcame Kevin Anderson 6-3 6-2 7-6.
Agnieszka Radwanska continued her perfect start to the year with her 13th successive victory to set up a quarter-final with Li Na.
—Photos by Agencies
Poland's Agnieszka Radwanska celebrates after beating Serbia's Ana Ivanovic. -Photo by Reuters
Serbia's Ana Ivanovic walks on court during her women's singles match against Poland's Agnieszka Radwanska. -Photo by AFP
Serbia's Novak Djokovic rips his shirt off as he celebrates his fourth round win over Switzerland's Stanislas Wawrinka. -Photo by AP
Serbia's Novak Djokovic, right, embraces Switzerland's Stanislas Wawrinka after winning their fourth round match. -Photo by AP
Fans wave during the men's singles match between Kevin Anderson of South Africa and Tomas Berdych of Czech Republic. -Photo by Reuters
Tomas Berdych of Czech Republic serves to Kevin Anderson of South Africa. -Photo by Reuters
France's Jo-Wilfried Tsonga celebrates after beating Slovenia's Blaz Kavcic. -Photo by AFP