Darren Cahill, the Australian tennis supercoach, can celebrate the remarkable achievement of guiding a fourth player to become a world No.1, as his brilliant young charge Jannik Sinner ascended to the top of the global men's game.
The 22-year-old Italian learned he had become Italy's first world No.1 player, man or woman, on Tuesday after the current main man Novak Djokovic was forced to pull out of the French Open with injury.
