World number one Serena Williams won the Miami WTA title for the seventh time Saturday with a 7-5, 6-1 win over China's Li Na. In a battle of the world's top two players, the US superstar took her tally of WTA titles to 59, adding a second trophy in 2014 to the one she lifted in Brisbane in January. Li, who won her second Grand Slam title at the Australian Open in January, has now lost 10 straight matches against Williams. Her only victory in their 12 meetings was back in 2008.