Novak Djokovic has the biggest test of his winning streak.

Roger Federer is leading against the hot-playing Serb two-sets to zero: 7-6 (7-5), 6-3. The match has been roughly two hours and Djokovic has been rather error prone in the second set.

Federer has been particularly sharp today. It will take an excellent comeback from Djokovic because he is simply being out played by the Swiss legend.

Djokovic had 19 winners after two sets, compared to Federer's 28. Meanwhile, Federer has approached the net more, and had nine aces compared Djokovic's two.

Mary Carillo stated that Federer is outplaying Djokovic in every category. Federer hasn't beaten Djokovic or Rafael Nadal this year, so this type of effort means a lot should Federer hold on for the victory.

Earlier today, Nadal defeated Andy Murray in a tight straight-set victory.