The Belarusian, who had faced a similar line of questioning after her first-round win, fired back that her off-court appearances had not come at the expense of her preparations for the Grand Slam.
"You guys are, like, a joke. Parties, fun... like, why would you even say that? Why would you even think about that? What kind of question is that?" the world number one said.
"Just because I posted, like, some activities with brands, and you think that I've been partying, not training?" she added, cutting the exchange short.
Turning to her performance on Wednesday, the four-time Grand Slam winner said she was pleased with both her level and her focus after another dominant performance at Arthur Ashe Stadium.
"I've been working really hard, but I feel like I'm kind of moving away from trying to be perfect on court," Sabalenka said. "I know that you cannot be perfect, and I'm just trying to work with what I have right now."
Sabalenka will continue her search for a third straight title in New York and avoid ending the year without a major, as she tries to recover her best form after not winning a title since claiming the Miami Open in March.
"I think I struggled a little bit in the middle of the season. Once again, I'm not going to defend myself or explain why, what happened, but I'm happy with my level," the 28-year-old said.
"I can definitely say that mentally I'm way stronger than I was in the middle of the season, and physically I also feel stronger. I feel like I'm on my level of play, and I just want to bring the right focus on the match every time."