Venus and Serena Williams were together again at Arthur Ashe Stadium on Friday, but injured world number one Serena could only watch as her older sister advanced to the fourth round of the US Open.

US third seed Venus, a seven-time Grand Slam champion, defeated Luxembourg’s Mandy Minella 6-2, 6-1 in 74 minutes.

Venus, the last woman to win back-to-back US Open titles from 2000 and 2001, will face Israeli 16th seed Shahar Peer for a quarter-final berth.

Wimbledon and Australian Open champion Serena, who suffered cuts to her feet that required surgery, was in the stands for the first time during one of her sister’s matches this week.

“It was good to see her,” Venus said.

“Usually we have a tournament together. Not this time. But it was good to have her back.”

Venus, like her sister, did not play during the run-up to the US Open because of an injury, with left knee pain keeping Venus idle but not slowing her now.

“So far I have been OK. I’m just looking to take my game to the next level every round,” she said.