The ATP's elite eight rubbed elbows with strangers and adoring fans on the London Tube.
Second seed hit with code violation for ball abuse.
The World No.4 vows to rehab and get back to the tour as soon as possible.
The two Czechs had fun at the expence of their mutual sponsor, Tag Heuer.
The former doubles World No.1 was also a Top-5 singles player and a Roland Garros runner-up.
The Swiss is hungry to crack another big milestone but doesn't want to let it ruin the vibe.
"Tsitsipas takes the towel after an ace or double fault," says Alexander Zverev.