Germany shrugged off the absence of world number two Alexander Zverev to sweep past Slovakia in their Davis Cup group stage finals opener on Tuesday as Canada beat Argentina.
Despite the absence of their top four players, including Zverev, the Germans dominated their Group C tie 3-0 in Zhuhai, China. The group also includes the United States and Chile.
Canada, the 2022 champions, eased past Argentina 2-1 in Group D action in Manchester, England.
Germany's Maximilian Marterer won the first point 6-4, 7-5 against Lukas Klein, with Yannick Hanfmann beating Jozef Kovalik 3-6, 6-3, 7-6 (7/3). Kevin Krawietz and Tim Puetz teamed up in the doubles to see off Klein and Igor Zelenay 7-5, 6-3 and wrap up the tie.
The United States, 32-time champions, open their campaign against Chile on Wednesday, followed by Slovakia on Friday and Germany on Saturday.
"We have a few days off so we can recover and do our best to win the next matches and still have a chance to go to the final," said Slovakia's Kovalik.
In Manchester, Canada's Denis Shapovalov battled past Francisco Cerundolo 7-5, 6-3 in Group D before Felix Auger-Aliassime eased past Sebastian Baez 6-3, 6-3.
Maximo Gonzalez and Andres Molteni teamed up in the doubles to beat Shapovalov and Vasek Pospisil 2-6, 6-3, 6-2.
Canada next play Finland on Thursday before taking on hosts Britain on Sunday.
"I feel great," said Shapovalov. "The last time I played in the Davis Cup we won the competition, so it was nice to be back and playing at such a high level. I want to build on this now."
Champions Italy open their title defence on Wednesday in Bologna against Brazil but without world number one Jannik Sinner, winner of the US Open at the weekend.
Italy are in the same Group A as Belgium, who bounced back from going 1-0 down to defeat the Netherlands 2-1.
In Group B, 10-time winners France lost 2-1 to Australia, losing finalists in 2022 and 2023.
