Djokovic defaulted from ATP Finals after kicking ball boy in the crotch

World number one Novak Djokovic has been defaulted from a tournament for the second time this year after another shocking display of frustration.

The 17-time slam champion was facing off against Germany's Alexander Zverev for a place in the semi-finals of the last tour-level event of the year, which the Serbian has won five times.

In an intense battle between two former champions, all was going according to plan for the 'Djoker', taking the first set 6-3. But Zverev fought back, engineering a break point in the ninth game of the second set with some brutal groundstrokes.

A clearly disgruntled Djokovic threw away the game with a mis-hit smash into the stands, before proceeding to scream in frustration and smash his racket on the ground. But that wasn't enough for the fiery Serb, who turned around to find something, or someone, else to vent his anger toward.

Unfortunately for 10-year-old ball boy Bradley Tate, he was but a few metres away from Djokovic's wrath. The 33-year-old bounded towards young Tate, launching one of his blue and white Asics shoes between the boy's legs, leaving him in a crying, crumpled heap on the floor.

Calmed by the gratifying experience, Djokovic sauntered back to his chair and started packing his bag before umpire Mohamed Lahyani had even called for his disqualification. It's the second time the controversial Serb has been defaulted in similar circumstances this year, having whacked a ball at a female line judge's throat at the US Open during his match against Spain's Pablo Carreño Busta.

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