It's not an official WTA stop, but Agnieszka Radwanska still had a big day at the Hopman Cup exhibition event, beating Serena Williams - twice in fact. Read about it here.
WTA Staff

PERTH, Australia - Agnieszka Radwanska led Poland to the Hopman Cup title on Saturday, not just beating Serena Williams in the women's singles match, but also in the mixed doubles match.

Eight countries sent teams to battle it out at the exhibition event in Perth this past week, playing each other in a series of three matches each - a women's singles match, a men's singles match and a mixed doubles match. A slew of WTA stars made the trip as well, including six of the Top 20 players in the world - Williams, Radwanska, Eugenie Bouchard, Flavia Pennetta, Lucie Safarova and Alizé Cornet.

At the end of the week only the USA and Poland were left standing, and Radwanska was the player of the day - she not only beat Williams in the singles match, 6-4, 6-7(3), 6-1, but she partnered Jerzy Janowicz to beat Williams and John Isner in the mixed doubles match, 7-5, 6-3. The final scoreline was 2-1, after Isner topped Janowicz in a tight one in a battle of massive servers, 7-6(10), 6-4.

Williams has beaten Radwanska in all eight of their WTA-level meetings, dropping just one set.

This is the first time in the 27 years of Hopman Cup that Poland came out with the title.

Williams has helped the USA to two titles before, in 2003 and 2008.

Here's Radwanska's post-match press conference after beating Williams...

And here's Radwanska and Janowicz after becoming Poland's first Hopman Cup champions.