What happened: The Williams sisters entered the women’s doubles draw as a wild-card pairing and opened play in Arthur Ashe Stadium. They also teamed at the Cincinnati Open last month.
Why it matters: Their 14 major doubles titles include two at the US Open. The reunion follows a planned Wimbledon pairing that ended before play because of a knee injury.
By the numbers: The sisters are 14-0 in Grand Slam doubles finals: six Wimbledon titles, four Australian Open titles, two French Open titles and two US Open titles.
What to watch: The No. 14 seeds stand between the wild-card pair and a place in the second round.