Nishikori was physically spent at the end of the Tsonga match. When he got a break up in the 5th he was just conserving energy on the Tsonga serve so he could hold his own. He's playing Mixed Doubles tomorrow as well. But he did play very, very well from the 2nd set when I turned on.
They looked dead on their feet at the end.
The looming doubles match wont help his score card against Andy though. Cant have much gas left in his tank!