Zverev cheekily unties umpire's shoelaces

Fans have seen a lot of strange exchanges between players and umps over the years, but here's a new one: untied shoelaces. Alexander Zverev, after an argument over whether he could wear his watch, untied umpire Carlos Bernardes' laces.

The 20-year-old German was leading 4-1 in the first set over Robin Haase at the time of the incident, when he was asked to remove his watch. Flustered that his sponsor would fine him, Zverev didn't comply without a little bit of rebellion. Zverev is a Richard Mille ambassador, and the company insists players wear the watch during play (Rafael Nadal also sports the luxury timepieces during play).

A watch-less Zverev would take the set, but ultimately fall, 3-6, 6-2, 6-2. The unexpected loss eliminates Zverev from the final tournament before the ATP Finals. He will, however, play some exhibition tennis at the Next Gen Finals in Milan, an event he withdrew from on account of making the London field.

In Milan, he'll play Stefanos Tsitsipas, the 19-year-old Greek No. 1 who is the first alternate in Milan and won the Genoa ATP Challenger in September.