NEW YORK — Venus Williams and Leylah Fernandez reached the women’s doubles quarterfinals at the US Open, defeating the 12th-seeded duo of Ekaterina Alexandrova and Zhang Shuai 6-3, 6-4 in their third-round match Monday in front of a capacity crowd at Louis Armstrong Stadium.

Williams and Fernandez had not played together until last week, when they received a wild-card entry into the field at the Grand Slam tournament. They are now 3-0 and have not lost a set in the process.

“We’re on the same wavelength, and hopefully we can keep it going,” Williams said.

With the stands packed at Armstrong and a wait to get in to see Williams and Fernandez, the 45-year-old American and 22-year-old Canadian needed just an hour and 14 minutes to move on.

“I have full confidence in Venus, and I hope she has full confidence in me during our match,” Fernandez said. “We’re just going out there, playing our game: Be offensive, aggressive and ready for the ball.”

Williams has called Fernandez her best partner other than sister Serena, with whom she won 14 Grand Slam doubles titles. Only one is still playing, but Venus is getting help from Serena from afar and wants more.

“She’s so happy for Leylah and I, and she’s given us advice,” Williams said. “We just need her in the box. So, my message is, ‘Serena, you need to show up.’”