She performed on Friday night at the stadium in New York in front of as many as 24,000 spectators, who enjoyed a gladiator fight and cheered for their pet in an attempt to continue her swan song. Unfortunately, they failed to do so, so Serena will retire with a total of 23 Grand Slam titles. She entered the US Open with just one win in the last 15 months and ranked 605th in the WTA rankings, but her performance reminded of some good times when she dominated women’s tennis.