Novak Djokovic's struggles at the Shanghai Masters continued in the Round of 16 against Jaume Munar, as the Serb threw up once again on the court in the middle of a match for the second day in a row. To make things worse, the 38-year-old veteran also added a new injury to the list of his ailments.The Shanghai Masters this year has been dominated by two main topics -- the speed of the courts and the brutally hot conditions during the day. While the first has not troubled Djokovic, the second certainly has.In his second-round win over Yannick Hanfmann, a tiring three-setter, the World No. 4 threw up halfway through, showing unusual signs of physical exhaustion. He said about the heat and the conditions afterwards in the press:"I’ve been saying it before, it’s the same for every player that steps out on the court, but it’s brutal. It’s brutal when you have over 80 per cent humidity day after day for the guys.""It’s brutal when you have over 80 per cent humidity day after day for the guys. Particularly when they are playing during the day with heat, with sun, it’s even more brutal. It is what it is, you just have to deal with it."On Tuesday, taking on Munar, Djokovic sailed through the first set 6-3, but not without incident. Four games in, the former World No. 1 suffered an injury to his ankle, and had to request for a medical timeout. Thankfully, the on-court physio appeared to have helped, as he went on to seal the seat comfortably.Things did not improve, however, as the heat got to the 24-time Grand Slam champion in Shanghai again. Djokovic ended up throwing up on the court again, and had to stop play for a while so he could clean up after himself.Munar, taking opportunity of his opponent's struggles, continued to exploit his physicality, forcing long rallies and letting the Serb tire himself out. The result was a 74 minute-long second set, which went 7-5 to the Spaniard. At the end of the set, an exhausted looking Djokovic opted for another medical timeout.Once again, it appeared to help the World No. 4, as he started the third set with an early break of serve and went 2-0 up. From there, he went on to take the set 6-2 to book his spot in the quarterfinals.Novak Djokovic makes record-breaking QF entry at Shanghai Masters2025 Shanghai Rolex Masters - Day 9 - Source: GettyWith his win over Jaume Munar, Novak Djokovic became the oldest man to reach the quarterfinals of a Masters 1000 event, beating the record previously held by Roger Federer. Federer had done it at the age of 38 years and 2 months, meaning Djokovic bettered him by two months at the Shanghai Masters.Up next, he will take on Zizou Bergs, who is in his maiden Masters 1000 quarterfinal. A win agains the Belgian would likely pit the Serb against Holger Rune in the semifinals, followed by a potential final against either Daniil Medvedev, Alex de Minaur or Felix Auger-Aliassime.