ATP roundup: Teenager Justin Engel wins opener in Kazakhstan
United States overcome Germany to top Davis Cup group as quarter-finals loom
Canada edge closer to Davis Cup Final Eight, Australia win after Machac withdraws
Australia edge France in doubles decider, Canada and Germany win in Davis Cup Finals
Zverev flexes big serve in first-round takedown of Marterer and advances in straight sets
ATP roundup: Shintaro Mochizuki stuns top seed Taylor Fritz in Tokyo
ATP roundup: Lorenzo Musetti posts win at Hamburg as Zverev strolls through
