Tennis icons Serena and Venus Williams will go head-to-head for the 30th time (in their professional careers) on Friday in the third round of the U.S. Open. Serena defeated Carina Witthoeft 6-2, 6-2 on Wednesday night to set up the showdown against her older sister, whom she is 17-12 against, including 10-5 at Grand Slam events.

“Normally I say cheer for me, but I say cheer for who you want, me or Venus,” said Serena, laughing, according to USA Today.

Serena added, “I never root against her, no matter what. So I think that's the toughest part for me. When you always want someone to win, to have to beat them. I know the same thing is for her. When she beats me, she always roots for me as well.”

Venus, ranked 16th, advanced to Friday's third round matchup by defeating Camila Giorgi 6-4, 7-5 earlier on Wednesday. 

According to USA Today, the two sisters first matched up against one another in the second round of the 1998 Australian Open, a match which Venus won. They last competed against each other in March during the third round at Indian Wells. Venus won that one as well.

Ahead of Friday's matchup, a 1991 video of Venus' appearance on TODAY has surfaced, in which she talks about how she "really started getting serious" with tennis at the age of 7. “I think when I was 5 years old, that’s when I think I started liking it a lot,” says Venus in the video. “I really started getting serious when I was 7. I think first it was my dad and my mom and my family, going out there to help me and push me.”