Slovakia reached the last eight of the Billie Jean King Cup Finals with a 2-1 comeback victory over 18-time champions the United States.

Taylor Townsend put the US ahead with a 7-5 6-4 victory over 17-year-old Renata Jamrichova in the first singles match.

But Slovakia's Rebecca Sramkova, ranked 43rd, caused an upset when she beat world number 11 Danielle Collins 6-2 7-5 to level the tie and force a doubles decider.

Tereza Mihalikova and Viktoria Hruncakova joined forces to defeat Townsend and Ashlyn Krueger 6-3 3-6 10-8 to set up a quarter-final encounter with Australia, who received a bye in the first round.

Earlier, Japan were the first team to claim a first-round win as they fought back to beat Romania 2-1 and seal their place in the last eight, where they will face 2023 runners-up Italy.

The tournament's opening tie between Spain and Poland was postponed on Wednesday because of a severe weather alert.

It has been moved to Friday, with play starting at 09:00 GMT before Great Britain face Germany from 16:00.