Serena Williams made an unsuccessful return to the WTA Tour as she joined Naomi Osaka in crashing out of the Internazionali BNL d'Italia in the second round on Wednesday. (More Sports News)
Williams was playing the 1,000th match of her glittering career against Nadia Podoroska, her first since losing in the Australian Open semi-finals to Osaka in February.
The American has experienced significant success in Rome, winning the title four times, but was always likely to be tested by a player who reached the French Open semi-finals last year.
And that proved the case as she slumped to a 7-6 (8-6) 7-5 defeat despite threatening a second set fightback.
Having won the first set on a tie-break, Podoroska continued to dominate the longer exchanges and went 5-2 up in the second.
From there, Williams won 12 straight points to level matters at 5-5, but Podoroska then claimed a nervy service hold to force the 23-time grand slam champion to serve to stay in the match.
She never came close to doing so as Williams was broken to love, a miscued forehand long giving Podoroska one of the biggest wins of her career.
Earlier in the day, Osaka was defeated in straight sets by Jessica Pegula.
Osaka has made no secret of her discomfort on clay, having never gone beyond the third round at Roland Garros.
All of her 10 WTA singles titles have come on the hard court and she was undone on the red dirt once more as Pegula prevailed 7-6 (7-2) 6-2.