BRISBANE, Australia (AFP) — With wins over the big three of world tennis already under his belt in 2019, Greek star Stefanos Tsitsipas said Thursday he believed he had the ammunition to take the world number one ranking. Tsitsipas became the youngest player to beat Rafael Nadal on clay and the youngest to record wins over Nadal, Roger Federer and Novak Djokovic during a stellar 2019 which saw him rise to world number five. […]