On Thursday night, Serena Williams beat her sister Venus Williams 6-2, 1-6, 6-3 to reach the U.S. Open semifinals. If Serena wins the U.S Open, she will become the first player since Steffi Graff to win all four majors (Serena already completed the “Serena Slam” when she won Wimbledon earlier this year). The sisters exchanged a tender moment after the match where, according to the New York Times, Venus congratulated Serena saying, “I’m so happy for you.”