All Tennis Players How Many Grand Slams Has Juan Martín del Potro Won? Juan Martín del Potro (Spanish pronunciation: [xwan maɾˈtin del ˈpotɾo]) (born 23 September 1988) is an Argentine professional tennis player.Juan Martín del Potro has won 1 Grand Slam.Juan Martín del Potro has won 1 Grand Slam. FacebookTwitterEmail How Many Grand Slams Has Madison Keys Won? How Many Grand Slams Has Jannik Sinner Won? How Many Majors Has John Isner Won?