A furious world number one Serena Williams destroyed her racquet in frustration and called the chair umpire a liar during Poland's historic Hopman Cup tennis title triumph on Saturday night.

Poland went ahead 1-0 after Agnieszka Radwanska shocked 18-time major champion Williams 6-4, 6-7 (7-3), 6-1 in front of 10,867 fans at Perth Arena.

Isner ensured the top seeds stayed alive with a 7-6 (12-10), 6-4 win over Jerzy Janowicz, but Poland prevailed 7-5, 6-3 in the deciding mixed doubles to snare their maiden Hopman Cup crown.

The mixed doubles was not without controversy.

With the US 2-1 down in the second set and staring at defeat, a point had to be replayed after Janowicz prematurely celebrated after he thought both Isner and Williams had struck the ball.

Williams believed the US should have been awarded the point due to Janowicz's distraction and a five-minute argument involving all four players, the chair umpire and the ITF referee ensued.

The Americans ended up winning the replay, but a few games later Williams twice smashed her racquet on the court after missing a simple backhand.

Radwanska leapt into the arms of Janowicz once the pair secured the Cup.

Williams, a two-time Hopman Cup champion, entered her singles 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 in Perth, the world number five 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.

All square ... Jerzy Janowicz (L) of Poland congratulates USA's John Isner. ( Getty Images: Will Russell )

Radwanska was part of the Polish team that lost last summer's Hopman Cup final to France and she would have been feeling a sense of deja vu after watching Janowicz falter.

The 203cm giant blew five set points in the first-set tiebreak, with Isner cruising to victory from that point on.

But the Polish pair produced the goods when it mattered most.

"It was one misunderstanding," Radwanska said of the mixed-doubles controversy.

"But oh well, the most important thing is we won.

"The title means a lot for us.

"I remember last year like it was a week ago. We lost the final in the mixed doubles, so I really wanted to win this one."

Williams said she enjoyed the tournament despite failing to come away with the title.

"Thank you John, you really held me up and gave us a chance in the final. Sorry I couldn't help you out," Williams said.

AAP