Nick Kyrgios crushed world number one Daniil Medvedev’s dreams of a title defense at the US Open on Sunday with a 7-6(11), 3-6, 6-3, 6-2 victory to reach the quarter-finals and ensure there will be a new top-ranked player when the tournament will be concluded. In a meeting worthy of a Broadway show between two of the game’s biggest servers and most combustible personalities, it was the fiery Australian who was the better in the match’s biggest moments, showing off a renewed focus and fitness. “It was an amazing match,” Kyrgios said in an on-court interview before a sold-out crowd at Arthur Ashe Stadium.