On Thursday, the Brazil Open in São Paulo used four former stray dogs taken in by a shelter as "ball dogs" to retrieve tennis balls from the court during a match between Spain’s Roberto Carbelles Baena and Portugal’s Gastao Elias.

The four lucky dogs were Frida, Mel, Isabelle and Costela (the Portugese word for "rib," so named because of how skinny he was when he was found in an abandoned lot).