Yahoo Sports reports: João Fonseca’s breakthrough performance at the French Open was just what tennis needs more of. The 19-year-old brought a new level of buzz to the sport with his vocal Brazilian fans, blistering forehands and a comeback victory for the ages over 39-year-old Novak Djokovic. Fonseca, however, ran out of energy in a straight-sets loss to Jakub Mensik in the quarterfinals late Tuesday.