In this instalment of our tennis series Beyond the Baseline, CGTN correspondent Wang Dong talks to World number five Alexander Zverev, who is also currently the youngest player in the top ten. The 21-year-old German won the third Masters title of his burgeoning career at the Madrid Open this year and reached his first grand slam quarter-final by going deep at the French Open, but pundits and players alike believe that's just the tip of the iceberg for the phenom's future achievements.