How Novak Djokovic’s Olympic run triggered memories of his fellow Golden Slam winner, Serena Williams

"My best tennis," said the 24-year-old German told Reuters. "Like, he's the favorite, but I know that. There's very few guys that can beat him in the world."

Still, Zverev has been one of them, getting two wins in eight career meetings against the Serb, including at the 2018 ATP Finals.

''I know I've done it before," he said.

But Djokovic is on a roll and dominating the field in historic fashion these days. Including his four wins at the Olympics, Djokovic is 38-3 on the season—with three Grand Slam titles to his name—and he hasn't dropped a set so far in Tokyo.

The winner will be guaranteed a medal, while the other will try for bronze in a playoff.

Advertising

Like Djokovic, Zverev hasn't dropped a set at the Olympic Games.

Speaking to German press, Zverev called the No. 1 "the toughest opponent in tennis" and said he had to play "almost his best tennis" to have "any chance at all."

But Zverev, who has won titles at Madrid and Acapulco this season, will be looking for a bit of Olympic inspiration, saying that competing at this special event will help him as he looks to do something special. A gold medal would be his biggest achievement since winning the aforementioned 2018 ATP Finals.

"You don't just play for yourself, or a team—you play for your country," said Zverev, who finished runner-up at last year's US Open. "My biggest motivation is to get a medal."

Zverev is No. 5 in the rankings.