Serena Williams wins Istanbul opener

Serena Williams got her WTA Championships campaign off to a winning start at the expense of Angelique Kerber this evening.

One break of serve was all that separated the two players in the opening set as two-time champion Williams ran out a 6-4 victor.

The second set was more straightforward for the American, who only dropped one game on her way to wrapping up the victory in the Red Group.

Williams has now won 44 of her last 46 matches in all competitions.

The other two players in their group, Victoria Azarenka and Li Na, will face each other tomorrow afternoon.