Poland’s Agnieszka Radwanska broke a long-standing hoodoo by beating world No.1 Serena Williams 6-4 6-7 (7-3) 6-1 in the Hopman Cup final on Saturday.

Big-serving American John Isner needs to beat world No.43 Jerzy Janowicz in the men’s singles rubber to keep the top-seeded US in the tie.

Williams, a two-time Hopman Cup champion, entered the match having won all of her previous eight contests against Radwanska.

Such was the dominance, Radwanska had only ever won one set against the American – in the 2012 Wimbledon final.

But Radwanska came out with all guns blazing at Perth Arena, with the world No.5 even serving for the match in the second set.

Williams broke back before winning the second-set tiebreak, but Radwanska came up with the goods when it mattered most in the third to secure the win in 125 minutes.

“When I go and play against her, you have nothing really to lose,” Radwanska said.

“She is No.1 in the world and a great champion.

“It doesn’t matter what the score is. It’s never over, she’s a great fighter. I’m just very happy that I could come back after that second set and play my good game in the third set.

“Wins like this always give a lot of confidence.”

Radwanska was part of the Polish team that lost last summer’s Hopman Cup final to France.

But with Poland now just one win away from the title, Radwanska has her hopes high of taking home the crown.