Switzerland made a strong start to its 2021 Billie Jean King Cup Finals campaign, sweeping past Germany 3-0 on Tuesday, while Slovakia grabbed a nail-biting 2-1 win over the 18-time champion United States.

Round-robin group play continued at the O2 Arena in Prague, on Day 2 of the preeminent team competition in women’s tennis. Twelve teams are split into four groups, with the group winners advancing to Friday’s knockout semifinals.

In their first tie of the event, Swiss Olympic medalists Belinda Bencic and Viktorija Golubic grabbed singles wins to give their squad an insurmountable 2-0 lead over the Germans early in the evening.

The World No.45 Golubic, who paired with Bencic to win the Olympic silver medal in women's doubles, started the day by defeating former Top 10 player Andrea Petkovic 6-4, 7-5. Golubic saved eight of the nine break points she faced.

Bencic, who won the Olympic gold medal in women’s singles this summer, overcame World No.9 Angelique Kerber 5-7, 6-2, 6-2 in just under two hours. Bencic slammed seven aces and grabbed the 26th Top 10 win of her career, improving to 5-2 in tour-level meetings against Kerber.

Golubic teamed with Jil Teichmann for a 52-minute 6-1, 6-2 victory over Anna-Lena Friedsam and Nastasja Schunk to complete the Swiss sweep.

Switzerland is aiming for its first Billie Jean King Cup title. Their nation’s best showing came in 1998, when it finished as runners-up to the five-time champions Spain.

Two-time Billie Jean King Cup champions Germany suffered its second Group D loss in two days. The team narrowly fell to the Czech Republic home team on opening night.

Slovakia had a much more difficult path to win its first tie of the event, edging the United States 2-1 in dramatic fashion.

The United States has the most Billie Jean King Cup titles in history with 18, most recently winning the crown in 2017. But Slovakia, which won its lone Billie Jean King Cup title to date in 2002, saved a tie point in the doubles match-tiebreak to upend the Americans and improve to 1-1 in Group C.

For the second day in a row, Viktoria Kuzmova put the Slovaks in front by winning the first singles match, this time defeating Shelby Rogers 6-4, 6-4. American Danielle Collins leveled the tie by beating Anna Karolina Schmiedlova, 6-3, 6-2.

The tie came down to the doubles match, where Caroline Dolehide and CoCo Vandeweghe of the U.S. gritted out a second-set tiebreak to force a decisive match-tiebreak. There, Kuzmova and Tereza Mihalikova stormed to an 8-4 lead for Slovakia, but the Americans pulled back to 8-8.

The Slovaks saw a match point slip away at 9-8, and the Americans would go on to grab a match point of their own at 10-9. But two impressive Kuzmova serves gave her team another match point at 11-10, and the Slovaks forced a volley error by Vandeweghe at that juncture, claiming a 6-2, 6-7(5), [12-10] win after 94 minutes.

Australia, Russia win day session ties

For the second time in as many days, the Billie Jean King Cup Finals began with an upset. Belgium had begun strongly by beating Belarus, but a day later fell to 2019 finalists Australia 2-1 in Group B. However, in Group A, four-time champion Russia was dominant in a 3-0 win over Canada, which consequently become the first team to be eliminated from the competition.

Already missing World No.1 Ashleigh Barty from their squad, Australia was dealt a further blow when Ajla Tomljanovic was ruled out of action due to illness. But this simply set the stage for an underdog triumph. Daria Gavrilova stunned Greet Minnen 6-4, 1-6, 6-4 in 2 hours and 3 minutes, before Storm Sanders pulled off an even bigger surprise by defeating Elise Mertens 3-6, 7-6(5), 6-0 in 2 hours and 6 minutes.

Former World No.20 Gavrilova had played just two tournaments in 2021, both in February's Australian swing, and the 27-year-old's ranking is down at No.412. However, she had routed Minnen 6-1, 6-0 in last year's Cagnes-sur-Mer ITF W80, and drew on that victory for a repeat in Prague.

Sanders had lost to Mertens 6-4, 6-1 in the first round of Roland Garros this year, and had lost all five of her previous meetings with Top 20 players. The World No.131 was two points from defeat on two occasions in the second set, but after edging a tight tiebreak rolled through the decider for a career-best victory.

Belgium was able to take some consolation revenge in the doubles, with Mertens and Minnen teaming up to beat Sanders and Ellen Perez 6-2, 6-4.

Meanwhile, Canada was unable to repeat its own underdog heroics of Day 1, when it had upset the defending champions France. The Russian team showed off its strength in depth, with four different players taking to the court to claim victories.

Read more: Russia eliminate Canada from Finals

Daria Kasatkina opened with a straightforward 6-3, 6-1 defeat of Carol Zhao in just 59 minutes, and she was followed by Anastasia Pavlyuchenkova, who outhit Rebecca Marino 6-4, 4-6, 6-2 in 1 hour and 38 minutes.

Veronika Kudermetova and Liudmila Samsonova completed a perfect tie for their country with a 6-3, 6-1 dismissal of Marino and Gabriela Dabrowski in only 53 minutes.