Serena Williams has reached at least the quarterfinals in each of her past nine appearances at the US Open and will take on Simona Halep for a place in the semifinals

World No.1 Serena Williams eased past 52nd-ranked Yaroslava Shvedova 6-2, 6-3 in her US Open fourth round tie to record her 308th Grand Slam match win

Venus Williams, who won the last of her seven Grand Slam titles at Wimbledon in 2008, is back in the last-four of a Grand Slam for the first time since the 2010 US Open

Williams, who at 31 could become the oldest US Open women's champion, and Stephens have not played since the 20-year-old phenom beat the four-time US Open champion 3-6, 7-5, 6-4 in an Australian Open quarter-final last January.

Stephens reached the round of 16 by beating 23rd-seeded Jamie Hampton 6-1, 6-3.

Del Potro stretched his Washington win streak to 14 matches by adding to the titles he won in the US capital in 2008 and 2009.

The unseeded Indo-German pair, which had shocked top seeds, lost 4-6 6-7(1) to the Filipino-Briton combo in the second round of the USD 1,295,790 hard court tournament.

They next face Treat Huey of Philippines and Briton Dominic Inglot in the quarter-finals.

Somdev, who created a record by retaining the NCAA title beating Isner 7-6 (7), 4-6, 7-6 (2) in 2007, was overpowered in their first meeting after that collegiate final here Thursday.

Somdev got the better of American Jesse Witten with a 7-5 6-0 scoreline. Sanam Singh had disappointment in store as he lost 0-6 5-7 to Australian 12th seed Samuel Groth.