(Reuters) - Novak Djokovic breezed into the third round of the Shanghai Masters with a 6-2 6-1 victory over Martin Klizan on Wednesday but Ivo Karlovic made sure Rafa Nadal had to work a lot harder.
Nadal eventually won through 7-5 6-7(4) 7-6(4) after two hours and 43 minutes of a closely-fought encounter.
After trailing 3-5 in the opening set, Nadal produced a series of stunning returns to break Karlovic in the 10th game to claim the lead.
The Croat, however, refused to give up, prevailing in the second set tie-break to force the decider, which again went to the wire before the Spaniard claimed victory.