Novak Djokovic battled through injury and intense heat to defeat Spain’s Jaume Munar and keep alive his pursuit of a fifth Shanghai Masters crown.
The 24-time Grand Slam champion, who required repeated treatment for a left ankle problem, dug deep to claim a 6-3 5-7 6-2 victory in two hours and 41 minutes.
Djokovic, ranked world number five, appeared to be struggling physically once again after vomiting during Sunday’s third-round win over Yannick Hanfmann in conditions exceeding 30°C and 80% humidity.
On Tuesday, the Serb called for a medical timeout after breaking to lead 3-1 in the opening set, grimacing as his ankle was treated.
He managed to consolidate his lead and secure the first set but continued to hobble between points.
Munar capitalised in the second, breaking at 5-4 to force a decider after Djokovic collapsed to the court, visibly exhausted following a gruelling rally.
The 37-year-old was helped to his chair and had his blood pressure checked before continuing.
Summoning his trademark resilience, Djokovic broke immediately in the third set and powered through to secure a place in the quarter-finals, where he will face Belgium’s Zizou Bergs.
The world number 44 fought back to beat 31st seed Gabriel Diallo 3-6 7-5 7-6 (10-8).
Elsewhere, 10th seed Holger Rune reached the last eight with a 6-4 6-7 (7-9) 6-3 win over Giovanni Mpetshi Perricard.
Afterwards, Rune called on the ATP Tour to introduce a heat rule similar to that used at Grand Slams, saying: “It’s brutal when you have over 80% humidity day after day. For those playing in the daytime heat and sun, it’s even more brutal.”
