Aussie hothead Nick Kyrgios is at it again, having a swipe at a ball boy during the Miami Open.

The king of tennis tantrums was roundly booed for his efforts, but this time there was a happy ending to a Kyrgios outburst.

While serving in the second set against Ivo Karlovic, Kyrgios became upset at the ball boy's technique.

"How am I supposed to catch that - it's right at my feet?" he complained.


But after beating Karlovic he approached the boy to make amends, playfully turning the kid's baseball hat around then giving him a keepsake towel.

Kyrgios later explained: "I was having a joke with him."