Shanghai: Novak Djokovic beat Gael Monfils 6-7 (4), 6-2, 6-4 in a highly taut, draining battle in the Shanghai Masters quarterfinals on Friday.
The defending champion looked out of sorts from the start. The Serbian hadn't been broken in his two previous matches in Shanghai, but he slumped serve twice in the first three games against Monfils.
The 42nd-ranked Monfils retaliated with pain in his abdominal muscles and couldn't break the Serbian again, after taking the first set.
Djokovic's semifinal foe will be Jo-Wilfried Tsonga, a 6-2, 6-3 winner over Germany's Florian Mayer.
Juan Martin del Potro also move up to the semifinals with a 6-3, 6-3 win over Nicolas Almagro and will meet either Rafael Nadal or Stanislas Wawrinka.