The 19-year-old was frustrated by the performance of her German opponent, Laura Siegemund, but even more so for being kept waiting when she was ready to serve.
But after coming from behind to win 3-6, 6-2, 6-4, the American said a chat with the former President and First Lady, who were at the US Open for a special ceremony, made her feel much better.
“I've met Mrs Obama before,” she said. “They told me it was just her initially. Then Mr Obama was there in the room, too. I was like, ‘Oh, my God!’
“I haven't soaked it in because I literally just walked in here. I think I'm going to never forget that moment for the rest of my life. I went from being really upset after a win to being really happy. So I'm glad I got to meet them. They gave me some good advice, too.
“They just told me, how I handle myself in these situations, she said it's good to speak up for myself. I think she was happy that I spoke up for myself today.”
Gauff had a lengthy conversation with the umpire about Siegemund, including when the German sat down on her chair after losing serve in a 26-minute opening game of the second set.
Gauff said she thought officials should be more consistent.
“I felt like the rules were being bent,” she said. “That's why a lot of players get mad when these time violations are called because one ref is letting them go over, the other is more strict on the time.
Former world No 1 Caroline Wozniacki, back after three and a half years out, having had two children, also advanced to round two.