Williams also joked that she refuses to retire before her counterpart Roger Federer. (AP)

Serena Williams says she can't beat herself at tennis—on Snapchat, that is. 

Users can now rally with the 23-time Grand Slam champion by way of bitmoji, and it's pretty fun. It even dresses your avatar in Wimbledon white. Just bear in mind, if you can't hold your own, a cartoon Williams gives you a low rating and looks at you disapprovingly. 

In real life, Williams won her first Wimbledon match as a mother on Monday, beating Arantxa Rus 7-5, 6-3 and extending her All England Club winning streak to 15. 

After the match, the seven-time Wimbledon champion was asked whether she, like Roger Federer, is aiming to play long enough for her child to remember watching her.  

"I'm just playing until Roger stops," Williams joked. "We in it together," she added. "As long as he's here, I'm going to try to be here."

 

Hummm that looks yummy #wimbledon go Mommy

A post shared by Alexis Olympia Ohanian, Jr. (@olympiaohanian) on

Federer, born the month before Williams, is currently the oldest man in the Top 100 at 36. 

Williams will face No. 135 Viktoriya Tomova in the second round, while Federer will play Lukas Lacko.