The six-time US Open champion showed excellent grit and fought until the last minute against her Australian opponent in what many expect to be the final tournament of her illustrious career.
Serena had earlier in August announced that it was time for her to ‘evolve away’ from the sport in an essay with Vogue magazine.
In a tightly fought contest, Serena backed up a huge crowd at the Arthur Ashe Stadium lost the first set by a narrow margin but bounced back to grab the second.
The visibly tired 40-year-old, however, found it hard to swing the match in her favour in the third set as Tomljanovic held her nerves to walk away with the win.
Nevertheless, it was not an easy task for Tomljanovic. The 23-time Grand Slam winner saved five match points down 5-1 in the third set and extended the game even further before going down to her 46th-ranked opponent.
Despite the loss, the fully packed stadium cheered and applauded one of the greatest tennis players to have played the sport.
Following what might have been her last US Open appearance, Serena made sure she thanked everyone in her post-match interview.
“Oh, my God, thank you so much. You guys were amazing today. I tried,” a teary-eyed Williams said to the crowd. She also thanked her parents, husband and older sister, Venus, a seven-time Grand Slam champion.
“I wouldn't be Serena if there wasn't Venus. So thank you, Venus,” Serena said.
When asked whether she would reconsider her plans about retirement, she replied, “"I don't think so, but you never know."