Azarenka to finish year as world number one after win ISTANBUL (Reuters) - Victoria Azarenka will end the year as world number one after the Belarussian beat China's Li Na 7-6 6-3 at the season-ending WTA Championships on Friday. Azarenka's victory meant she finished second in Group A behind Serena Williams. The American won all three of her round-robin matches while the world number one registered two victories and a defeat by Williams. Both players have qualified for the semi-finals.