Top seed Rafael Nadal marched into the last 16 of the Shanghai Masters with a thoroughly entertaining 6-2 6-7 6-4 victory over American James Blake on Wednesday.
US Open champion Juan Martin Del Potro, however, joined the growing casualty list at the $3.24-million tournament, retiring because of a wrist injury while 7-5 2-1 down to Austrian Jurgen Melzer.
The third-seed follows Andy Roddick and Tommy Haas out of the tournament with injury, while Roger Federer and Andy Murray elected not to play on fitness grounds.
“I had this injury in Miami this year and I don't want to risk for the end of the season,” said the Argentine. “I'm a little sorry. It's a big tournament here in Shanghai, very important for me, but if I want to have a good finish this season, I have to recover.”
Nadal has not reached a final since the Madrid Masters in May and will continue his comeback from knee and abdominal injuries against Tommy Robredo on Thursday.
Jo-Wilfried Tsonga dismissed Chinese wildcard Zeng Shaoxuan 6-3 6-3 and set up a third-round clash with Robin Soderling, who beat Nicolas Almagro 6-4 7-5.
Ivan Ljubicic upset seventh seed Fernando Verdasco 6-4 7-6 and will now meet Gael Monfils in the last 16 after the French rallied from a break down in the third set to beat Lleyton Hewitt 4-6 6-4 6-2.