By Alek Arend A new superstar is emerging his men’s tennis – and he’s just 19 years old. On Saturday, Carlos Alcaraz Garfia became the first-ever player in men’s tennis history to beat both Rafael Nadal and Novak Djokovic in the same clay court tournament. Yesterday, Alcaraz beat Nadal 6-2, 1-6, 6-3. Today, after falling behind to Djokovic and losing the first set, he rattled off back-to-back set wins to defeat Djokovic and the match. Alcaraz will play in the Madrid Open Final on Sunday. “Carlos Alcaraz just became the first player to ever defeat Nadal and Djokovic in back-to-back matches on c…