While Djokovic found himself somewhat vexed by the situation, he remained in good spirits after reaching a ninth consecutive quarter-final at Roland Garros, particularly after such a hard year due to his elbow injury.
The 12-time Grand Slam victor defeated Fernando Verdasco at Roland Garros.
Resurgent former champion Novak Djokovic reached the French Open quarter-finals for the 12th time on Sunday as he subdued feisty Spanish veteran Fernando Verdasco 6-3 6-4 6-2.
"I just questioned the decision from the chair umpire, actually, that he's listening to the grounds people".More news: New Italian govt vows to create jobs, deport migrants
At 6-6, and having already saved two set points, Djokovic took aim at an open court with his forehand but his passing shot flicked the net and bounced wide, provoking the racket-smashing tantrum that earned him a warning. Speaking about Djokovic's next match against Spain's Fernando Verdasco, Wilander says, "Djokovic will know that it's a match he could lose but I think we are seeing a more determined Djokovic".
Verdasco, who beat fourth seed Grigor Dimitrov in straight sets in the previous round, needed treatment for blisters as Djokovic was made to wait before serving out for two-love lead.
"It doesn't seem like they care too much about our opinion, and that's something I don't like".
Seeded 20th and with lower expectations than normal coming in after an injury-disrupted year, the 31-year-old Djokovic appears to be rediscovering the old fire.More news: Melania Trump skipping G7, North Korea summits
But Zverev fended off break points as he levelled in the fourth, and then struck with an early break in the decider.
Djokovic, who arrived in the French capital short of form and confidence, has only lost one set on his run to the last eight of the tournament and will next meet Marco Cecchinato after the world No 72 defeated David Goffin 7-5 4-6 6-0 6-3.
"It is a pleasure to play against Novak, this moment is unbelievable for me".
"It's important for me, especially considering all the circumstances that I was in in the last 15 months", he said. "I have been many, many times in quarters of Roland Garros and all the slams, and of course I do appreciate it, considering it's a different kind of situation for me". "I don't want to stop here".More news: North Korea 'replaces top three military officials'