Alexander Zverev has proven himself as the best of tennis' new generation of men's players following his maiden ATP Finals triumph where he beat Roger Federer and Novak Djokovic in consecutive days, German great Boris Becker has said.
After overcoming 20-times Grand Slam winner Federer in the semi-finals in London on Saturday, the 21-year-old Zverev beat world number one Djokovic 6-4 6-3 the next day to claim the biggest crown of his career so far.
Victory meant Zverev, who has also won titles in Washington, Madrid and Munich this season, will finish in the top four of the world rankings for a second straight year.
"For years we have been saying tennis needs new faces and strong new players - and he's proved he is the best of the next generation," Becker, the last German to win the ATP Finals in 1995, told the BBC.
"Beating Novak Djokovic in the final was a big upset and a big victory for Sascha (Zverev). It was the big match which we were all waiting for from him.
"Yes... he's beaten Djokovic and Federer before, but to beat them back-to-back in one of the biggest tournaments in the world tells him, most importantly, but also the world, that he is going to be the next big thing."
Becker, a six-time Grand Slam winner, said Zverev had the potential to be the "new superstar" of world tennis and backed his compatriot to deliver on his promise under coach Ivan Lendl.
Eight-time major champion Lendl and Zverev have been working together since August.
"I'm happy he now has Lendl as a coach because Ivan can tell him the same stories I can tell him and brings an understanding of the game to his team," the 50-year-old Becker added.
"Often it is a small margin and when you have someone on the sideline who has been there it has a big effect... It's brave for Sascha to ask someone like Lendl to join his coaching team. It shows you Sascha's motivation and his goals for the future.
"He wants to win and be the best so he is surrounding himself with the best."
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