The 2011 titlist withstood a challenging third round encounter against Gilles Simon, as he beat the Frenchman 6-4, 6-2, 6-4 in two hours and 12 minutes.
No.1 seed spent 3 hours and 17 minutes in seeing off world no.38 Radek Stepanek 6-4, 6-3, 6-7 (5), 7-6 (5) in their second round encounter on Wednesday.