NEW YORK: A defiant Serena Williams bid an emotional good-bye to the US Open with a third-round loss to Ajla Tomljanovic on Friday (Sep 3), in what may have been the last singles match of her glittering career.Defeat has always been hard to swallow for the fiercely competitive Williams and no doubt the 7-5 6-7 (4) 6-1 loss to the 46th ranked Australian stung her to her core.But after a joyous run into the third round there was no shame in a loss to the gritty Tomljanovic, allowing the 23-times Grand Slam winner to exit with dignity intact and head held high.Her three matches, highlighted by a second-round win over world number two Anett Kontaveit, were a gift to her fans, the relentless never surrender attitude that made her tennis' dominant player for over two decades on display right until the very final point."Clearly I'm still capable," Williams told reporters. "But it takes a lot more than that."I'm ready to be a mom, explore a different version of Serena."Technically in the world I'm still super young, so I want to have a little bit of a life while I'm still walking."I have such a bright future ahead of me."Always up for a fight, the 40-year-old came out swinging, forcing Tomljanovic to go the distance.The Australian needed six match points to deliver the knockout punch and bring an end to an engrossing three-plus-hour slugfest.Without a WTA Tour title and never before going beyond the quarter-finals of any Grand Slam, Tomljanovic has spent most her career as one of tennis' lesser-known names.But now the 29-year-old will live on forever in tennis history and at sport trivia pub nights, as the answer to the question; "Who was the last player to beat Serena Williams"."No one's going to pronounce my name right,"