Novak Djokovic fell in the final round of the Miami Open to 19-year-old Jakub Mensik in straight sets, 7-6, 7-6, on Sunday. Mensik, playing in his first final, earned his spot after defeating No. 3 seed Taylor Fritz in the semifinals and became the second-youngest champion in tournament history, per ATP Tour.

Watching Djokovic has become a live-action demonstration of a tennis player figuring out his limits from match to match and week to week.

Ranked 54th entering the tournament, the Czech Republic teenager plowed through with poise and a stellar 130 mph serve.