Victoria Azarenka of Belarus pumps her fist after winning a point against Serena Williams of the US during their championship match at the women's Cincinnati Open tennis tournament in Cincinnati, Ohio, Aug 18, 2013. [Photo/Agencies]

Serena Williams of the US hits a return to Victoria Azarenka of Belarus during their championship match at the women's Cincinnati Open tennis tournament in Cincinnati, Ohio, Aug 18, 2013. [Photo/Agencies]

Victoria Azarenka won a showdown between the world's two top ranked players beating number one Serena Williams in a three set thriller 2-6 6-2 7-6 in the final of the Western and Southern Open on Sunday.

For two hours and 30 minutes, Azarenka and Williams engaged in a seesaw center court battle before the second ranked Belarusian finally clinched the victory, winning a nervy tiebreak 8-6 to stop the American from ticking one 'to do' item off her 'bucket list'.

In a career that has generated 54 singles titles, including 16 Grand Slams, Williams had won just about everything there is to win in her sport - but not Cincinnati, one of the WTA Tour's most prestigious tournaments.

Cincinnati will remain a hole on her resume for at least another year after Azarenka answered the challenge claiming just her third win in 15 tries against the 31-year-old American.