Match of the day went to Karolina Pilskova defeating Venus Williams
Serena Williams scored her 308th Grand Slam win on her way to the US Open quarterfinals, making her the winningest player - male or female - in the Open Era.
Match of the day saw Pavlyuchenkova prevail in a three-hour affair over 2015 quarterfinalist Kristina Mladenovic
Chris oddo WTA.com
Venus Williams began her record-breaking 72nd Grand Slam campaign with a hard-fought win over Kateryna Kozlova on Arthur Ashe Stadium.
Photography: Michael Bradley