Sloane Stephens beat Serena Williams at the Australian Open back in January and now says that Williams has been a sore loser ever since.

The 20-year-old, who once looked up to Williams, has had a change of heart after defeating the tennis pro 3-6, 7-5, 6-4 in the quarterfinals of the Open.

“She’s not said one word to me, not spoken to me, not said hi, not looked my way, not been in the same room with me since I played her in Australia,” Stephens revealed in the upcoming issue of ESPN.

“And that should tell everyone something, how she went from saying all these nice things about me to unfollowing me on Twitter," Stephens continued.

Stephens also said that Williams was not a good mentor, barely speaking or giving advice to the newcomer, who began tennis at an early age as did Williams.

“For the first 16 years of my life, she said one word to me and was never involved in my tennis whatsoever. I really don’t think it’s that big of a deal that she’s not involved now. If you mentor someone, that means you speak to them, that means you help them, that means you know about their life, that means you care about them. Are any of those things true at this moment?" 

After losing to Stephens at the Australian Open, Williams even took to Twitter to write the cryptic message, “I made you,” which was likely directed at the young tennis player.

She went on to say that even when she was younger, both Serena and her sister Venus were unkind toward her. Stephens had a poster and waited three hours for them to sign it, but both walked right past her several times.

Both Serena Williams and Sloane Stephens are set to play in the French Open, which begins at the end of the month.