Sydney: Canadian Denis Shapovalov picked up his second win against a top-10 player at the ATP Cup team event on Tuesday with a 6-2, 6-2 thumping of Alexander Zverev as the German continued to struggle with his serve ahead of this month's Australian Open.
Shapovalov, 20, needed just 70 minutes to brush aside world No. 7 Zverev, who lost his third straight singles before the year's first Grand Slam starting in Melbourne on January 20.
Zverev, the 2018 ATP Finals champion, served seven double faults against Shapovalov to take his total for the tournament to 31.
"There's a lot of things that I still need to improve, but it's the start of the season," Zverev said.
"I need to find my rhythm."
Shapovalov returned with teammate Felix Auger-Aliassime to win the deciding doubles rubber against Kevin Krawietz and Andreas Mies 6-3, 7-6(4), earning Canada a 2-1 win in the tie to keep them in the hunt for the quarterfinals.
All six group winners and the two best second-placed teams will advance to the final eight in Sydney.
Hosts Australia, Serbia and Russia have already qualified.
"I'm really happy to get the win and hopefully we can go through," said Shapovalov, who defeated Greek world No. 6 Stefanos Tsitsipas in his opening match.
"I feel like we're definitely one of the top teams, and I feel like we definitely deserve to go to Sydney. Hopefully, if we do get that chance, we can do some really big damage."
The world's top players have assembled for the $15 million ATP Cup, which features 24 nations competing in Perth, Brisbane and Sydney over 10 days.
Russian Daniil Medvedev, the US Open finalist and world No.5, won his third straight singles rubber in Perth, beating Norway's Casper Ruud 6-3, 7-6(6).
Dan Evans completed a one-sided 6-2, 6-2 win over Radu Albot to seal Britain's victory over Moldova in Sydney.