Serena Williams ties Open-era mark with 306th Grand Slam match win

— -- NEW YORK --? Serena Williams tied Martina Navratilova's professional-era women's record with her 306th career victory in a Grand Slam match, beating Vania King 6-3, 6-3 on Thursday night to reach the US Open's third round.

Hitting 13 aces Thursday night, Williams improved to 306-42 in matches at major tournaments, a winning percentage of .879.

Because of Thursday's wet weather, action around the grounds was limited until the early evening, but matches kept coming under the roof at Arthur Ashe Stadium.

"It was definitely a little different playing with Ashe closed," said Williams, who was clearly displeased with winning only 13 of 40 points on King's first serves. "But it still feels great."

Only Roger Federer, with 307, has won more Grand Slam matches than Williams in the Open era, which dates to 1968.

Williams can match Federer's total by beating 47th-ranked Johanna Larsson of Sweden on Saturday.?

Earlier, Serena's older sister, seven-time major champion? Venus Williams, also breezed through her second-round match. Venus had spent 2 hours, 42 minutes on court in a tense three-set victory over 93rd-ranked Kateryna Kozlova on Tuesday. But against German veteran Julia Goerges on Thursday, she won 6-2, 6-3 in 78 minutes.

Venus had just 17 unforced errors, in complete contrast to the 63 in her first-round win.

The oldest player in the draw at 36, Venus, who is the No. 6 seed, is coming off a semifinal appearance at Wimbledon, her deepest run at a major since 2010.

The Associated Press contributed to this report.