The 23-year-old cancelled out Remo Freuler's opener with a terrific finish from Ricardo Rodriguez's cross in first-half stoppage time and, following Hakan Calhanoglu's unstoppable strike, wrapped up the result by heading in a corner on Saturday.
Piatek has now scored six times in his past four appearances and the quality of his inventive equaliser did not go unnoticed by Rossoneri boss Gattuso.
"In seven to eight months [in Serie A] everyone has become accustomed to these goals," Gattuso told Sky Sport Italia .
"Piatek is a player that lives to score goals. He is doing well with his movements and he has superior technical skills.
"We are happy to have him with us.
"In general, I don't want to hear individuals spoken about, but the group. Results are helping us, they're bringing enthusiasm. We need to continue like this and work with a sense of calm."
42 - In all their previous 13 campaigns in the three points for a win era, AC #Milan have always finished in the Top-4 of the table when they managed at least 42 points after 24 MDs. Aim. #SerieATIM #AtalantaMilan pic.twitter.com/keckCJrQrP— OptaPaolo (@OptaPaolo) February 16, 2019
"He's a great coach and he was a legend for this club," Piatek told Milan TV .
"I feel like I'm in a family here, I feel very good and I'm happy. I need to carry on like this while looking to help the team."
Atalanta's first loss in seven Serie A matches saw them slide back to seventh and head coach Gian Piero Gasperini was left searching for answers as to the confidence that deserted his team.
"I don't know why we lost conviction," Gasperini said. "It must no longer happen because this Atalanta side must play without pressure
"We are not a team that is supposed to make the Champions League."