\n<\/p>\n
Serena was playing her first match since Wimbledon, while Venus has played singles and doubles at three hard-court events in recent weeks.<\/p>\n
The pair made a poor start against Ukraine’s Kostyuk and American Stearns before shaking off what Serena called “a little rust” in the second set.<\/p>\n
They quickly went down 6-0 in the deciding 10-point tie-break but fought back impressively.<\/p>\n
Serena produced two service winners to force the tie-break back on serve, but Kostyuk and Stearns held firm before securing victory on a double fault from Venus.<\/p>\n
“I thought it was fun, it was special, it was good,” Serena said.<\/p>\n
“We were starting to feel it. It was really cool to be able to do this again.”<\/p>\n
The sisters would need wildcards to play either singles or doubles at the US Open, which begins on Sunday, 30 August.<\/p>\n
Serena – who described her knee injury as “a little traumatic experience, but what doesn’t kill you makes you stronger” – has only played one singles match since her return.<\/p>\n
Venus has lost her past 13 singles matches but has had more success in the doubles, reaching the quarter-finals of the women’s tournament in New York last year.<\/p>\n
At their peak, they won 14 Grand Slam doubles titles together and three Olympic gold medals.<\/p>\n<\/div>\n