Last Friday's (September 3) third-round U.S. Open match, though resulting in a loss for Williams, was the most-watched tennis broadcast in ESPN's 43-year history, Deadline reports.
Williams' finale, an almost 3-hour broadcast, garnered an average of 4.8 million viewers, and viewership peaked during the final set with 6.9 million people tuning in.
According to ESPN, the third-round match beat the previous record set by Roger Federer and Andy Murray's 2012 finals match in Wimbledon, which saw 3.9 million viewers.
The tennis superstar's probable last match was also ESPN's most-watched program of the day for both "broadcast and cable networks in total viewers," beating out the ratings of several college football games.
Williams fell to Australian tennis star Ajla Tomljanović in the third round of the U.S. Open held at Arthur Ashe Stadium in New York.
Following the match, when asked whether she would reconsider her retirement from tennis, Williams said, "I don't think so, but you never know."
Before the loss, Williams' performances during the first two rounds wowed the star-studded New York crowd and garnered higher-than-usual ratings for ESPN.
Her opening night victory over Danka Kovinic averaged 2.7 million viewers. The 23-time Grand Slam champion also brought in an average of 3.6 million viewers for her second-round match, where she defeated Anett Kontaveit, who was ranked the No. 2 player in the world.
"These are the most-viewed first five days of the U.S. Open on record on ESPN networks," the network said in a press release.