Three Grand Slam champions scored notable victories on Day 1 of the Billie Jean King Cup Qualifiers, with Naomi Osaka and Iga Swiatek both giving their countries early leads and Emma Raducanu notching a milestone win on clay.

The winners of this weekend's eight Billie Jean King Cup Qualifiers ties will advance to November's Billie Jean King Cup Finals in Seville.

Osaka spearheads Japanese charge on home soil

Former World No.1 Osaka made a victorious return to Billie Jean King Cup action on Friday, defeating Yulia Putintseva 6-2, 7-6(5) in Tokyo to give Japan an early 2-0 lead over Kazakhstan.

Earlier, No.79-ranked Nao Hibino had kicked off the hosts' campaign with a 6-1, 6-0 rout of Anna Danilina in just 57 minutes.

Osaka improved her overall Billie Jean King Cup record to 6-2 with an impressive display against an opponent she has previously struggled with. She lost her first three encounters with Putintseva in 2018-19, but has now scored two consecutive wins against the Kazakhstani, both on home soil.

After a dominant opening set, Osaka held her nerve in a tightly-contested second set that went down to the wire, converting her first match point with a pinpoint backhand winner down the line.

Currently ranked No.193 after returning from maternity leave in January, Osaka was making her first Billie Jean King Cup appearance since February 2020.

Raducanu comeback draws Great Britain level with France

With France hosting Great Britain on clay in Le Portel, the three-time champions started the tie with a significant home advantage. This was borne out across the first match and a half.

Diane Parry turned in a polished performance to demolish Katie Boulter 6-2, 6-0, winning 12 straight games from 2-0 down. No.49-ranked Parry, who cracked the Top 50 for the first time this week, used her variety and courtcraft effectively to expose her opponent's inexperience on the surface. Boulter has yet to play a tour-level match on clay.

However, former US Open champion Raducanu pulled off a 3-6, 6-3, 6-2 comeback from a set and a break down against Caroline Garcia to level the tie. Though the Briton went toe-to-toe with Garcia from the baseline in the first set, it was her improved ability to read the Frenchwoman's serve that was key to the turnaround.

Raducanu won just three points against the Garcia first serve in the first set, but over half of those in the second. In the decider, Garcia's first serve percentage plummeted to 38%, and Raducanu took full advantage by repeatedly teeing off on her second serve for clean winners. In total, the 21-year-old tallied 25 winners -- including 16 off the forehand side -- to only 11 unforced errors.

The result was Raducanu's first Top 30 win since defeating Beatriz Haddad Maia at Indian Wells 2023, and the first Top 30 win of her career on clay.

Swiatek, Frech put Poland up on Switzerland

Switzerland, the 2022 champions, also had a home-court advantage, hosting Poland on the indoor hard courts of Biel. But with Belinda Bencic, a lynchpin of the Swiss team over the years, currently on maternity leave, the rankings heavily favored their guests.

World No.1 Swiatek had not faced Simona Waltert since their junior days, having defeated her in the second round of Wimbledon juniors in 2018 en route to the title. She reprised that result 6-3, 6-1, though the scoreline belies the effort she needed to quell No.158-ranked Waltert. Swiatek had to face 14 break points over the course of the match, and succeeded in fending off 13 of them.

Magdalena Frech gave the visitors a 2-0 lead at the end of Day 1 after defeating Celine Naef 6-7(8), 7-5, 6-3 in a top-quality thriller over 2 hours and 52 minutes. The 18-year-old Swiss demonstrated superb point construction and superior aggression to edge the first set, and she served for the match at 5-4 in the second.

But Frech hung in a number of extended rallies to gradually turn the contest in her favor, and pulled away in the deciding set to outlast the teenager.

Americans outlast Belgian teens

Jessica Pegula and Emma Navarro needed to summon all of their elite form in order to build a 2-0 lead over Belgium on Friday in Florida. The pair of Top 25 players had to fight past two 19-year-olds, neither of whom had previously faced a Top 100 player in their careers.

World No.5 Pegula battled to a 4-6, 6-2, 6-3 victory over big-hitting Sofia Costoulas, a recent Top 5 junior. World No.21 Navarro kept the Americans in front with a 4-6, 6-4, 6-3 comeback over Hanne Vandewinkel, closing out a challenging day versus two impressive youngsters.

Australia, Slovakia, Ukraine, Germany take early leads

In Brisbane, hosts Australia took a 2-0 lead over Mexico on the first day. Arina Rodionova, who became the oldest player ever to debut inside the Top 100 earlier this year, kicked off the tie by coming from a set down to defeat Giuliana Olmos 3-6, 6-3, 6-1.

Former No.20 Daria Saville backed up her compatriot by racing through her rubber against Marcela Zacarias 6-1, 6-0 in just 51 minutes.

In Bratislava, hosts Slovakia also ended Day 1 with a 2-0 lead over Slovenia. Anna Karolina Schmiedlova defeated 18-year-old Ela Milic 6-4, 6-3, before Viktoria Hruncakova came through 6-1, 5-7, 6-3 over Veronika Erjavec.

Ukraine also wrapped up the first day with a 2-0 lead over Romania. Lesia Tsurenko started the tie with a 3-6, 6-2, 6-0 comeback over Ana Bogdan. Ukrainian No.1 Elina Svitolina followed with a 6-3, 7-5 win against last week's Charleston quarterfinalist Jaqueline Cristian.

Late in the day, Germany built a 2-0 lead over home team Brazil. Laura Siegemund picked up the 19th Top 20 win of her career with a 6-4, 6-2 win over Beatriz Haddad Maia. Tatjana Maria added to the Germans' advantage with a 2-6, 6-4, 6-4 victory over Laura Pigossi.