Former world number one, Serena Williams crashed out of the Cincinnati Open after losing to Petra Kvitova of the Czech Republic in the Second Round on Tuesday.
The 32 year old, Williams lost 6-3, 2-6, 6-3.
It was Serena’s second-round loss comes on the back of her heaviest career defeat, a 6-1 6-0 loss to Britain’s Johanna Konta in the Silicon Valley Classic First Round.
“I’m still at the very beginning,” Williams, a 23-time Grand Slam champion told the BBC after the defeat.
“I’m just going to continue to work hard, and hopefully I’ll start winning more matches.”
Williams’, a runner-up at this year’s Wimbledon, withdrew from last week’s Rogers Cup in Canada for “personal reasons” after struggling with post-natal emotions.
World number two Roger Federer overcame Germany’s Peter Gojowczyk 6-4 6-4.
The Swiss will play Argentina’s world number 50 Leonardo Mayer in the next round.
British number one Kyle Edmund lost 6-4 7-5 to Canadian Denis Shapovalov in the second round in Cincinnati while Nick Kyrgios also defeated Denis Kudla 6-7 (2-7) 7-5 7-6 (9-7).