Iga Swiatek and Emma Raducanu were both victorious as Poland and Great Britain won their first-round ties at the Billie Jean King Cup Finals on Friday.

Poland won both of their singles matches against Spain in Malaga, while Britain did likewise versus Germany to seal their own spot in the competition's last eight.

World number two Swiatek clinched Poland's progress with a 6-3 6-7 (6-8) 6-1 victory over Paula Badosa, after Magda Linette had put them ahead by beating Sara Sorribes Tormo in a gruelling three-hour, 51-minute affair.

Speaking after her own win, Swiatek hailed the endurance of team-mate Linette, who triumphed 7-6 (8-6) 2-6 6-4.

"I wouldn't say that I pushed us to the quarter-finals, because Magda pushed us to the quarter-finals, so we did it together," the five-time grand slam champion said.

"I'm glad that we won a match as Team Poland. I felt like it was my best match since the US Open. I knew that I could come back in the third set and try to win it for Poland."

Later on Friday, Great Britain were propelled to victory by Raducanu and Katie Boulter, both of whom were straight-sets victors.

Raducanu, playing her first match in almost two months after recovering from a foot injury, beat Jule Niemeier 6-4 6-4.

The 2021 US Open champion started well and her effective serve was a key feature of the opening set, though she later required six match points to get over the line as Niemeier refused to go down without a fight.

Britain will face defending champions Canada in the last eight after Boulter raced to an impressive 6-1 6-2 victory over Laura Siegemund, ensuring there was no need for Olivia Nicholls and Heather Watson to team up for a deciding doubles match.