Djokovic returns for Simon challenge

Melbourne: Defending champion Novak Djokovic returns to Rod Laver Arena for clash against Gilles Simon on Sunday as he looks to seal his place in the quarter-finals of the Australian Open for the ninth year in a row.
The Serbian world number one, farmed out to Margaret Court Arena for his third round victory over Andreas Seppi, has yet to lose a set in the tournament but might find that record under threat against the indefatigable Frenchman.
In a high quality opening session on the main stadium court, the five-times champion's fourth round match follows that of his counterpart in the women's draw, Serena Williams.
Williams, who already has six Melbourne Park titles in her trophy cabinet, has been similarly untroubled in reaching the last 16 and can be expected to easily deal with 21-year-old number 58 Margarita Gasparyan.
Gasparyan's rather more successful compatriot Maria Sharapova, the 2008 champion, opens the day on Rod Laver Arena with an intriguing intergenerational battle against Swiss teenager Belinda Bencic.
Parochial concerns mean Australia's Daria Garvrilova takes the spotlight in the evening primetime slot in Melbourne Park's biggest arena for her contest against 10th seed Carla Suarez Navarro.
Four-times champion Roger Federer restores some grand slam pedigree to the court when he meets Belgian David Goffin in the final match of the day.
Sixth seed Tomas Berdych takes on Roberto Bautista Agut out on Margaret Court Arena, while seventh seed Kei Nishikori's attempt to avenge his five-set loss to Jo-Wilfried Tsonga at last year's French Open is on Hisense Arena.
Women's fourth seed Agnieszka Radwanska also plays on Hisense as she faces Anna-Lena Friedsam, who upset U.S. Open runner-up Roberta Vinci in round three, for a place in the last eight.