0243 GMT November 13, 2019
In an incident-packed match, Zverev apologized to a television cameraman after the young German accidentally hit a ball flush into his jaw in winning a point, AFP reported.
The 22-year-old was also seen by a doctor in the first set and in another colorful moment Zverev smashed his racquet on the floor during the mammoth first-set tie break.
Zverev, ranked sixth in the world but suffering a poor season, was pushed all the way by the 71st-ranked Chardy before finally emerging in one hour and 48 minutes.
"I felt a little dizzy and my head was spinning a little bit," he said, explaining why he asked to see a doctor.
"But the doctor didn't speak a lot of English and all he wanted to do was give me pills for everything possible so I said I'd rather not take any pills and see if I feel better."
The second-set tie break had a lighter moment – Zverev losing his grip while hitting a shot, his racquet whizzing into the crowd.
"It was definitely interesting," the German smiled, referencing his flying racquet and his smash which hit the cameraman – neither intentional, he stressed.
"The racquet accelerated too fast and flew about 10 rows up so I hope I did not hurt or hit anybody, but it was definitely not on purpose."
Zverev has long been talked about as the next big thing in men's tennis, but only one of his 11 career titles has come this year. He is yet to win a Grand Slam.
The fifth seed will play Andrey Rublev of Russia in the last 16.