After one year in the second division, the Magpies beat Preston North End 4-1 on Monday to confirm their return.
The Ghanaian lasted the entire duration of the fixture at St. James' Park, scoring his club's second goal of the night.
“Benitez is a great human being and he was very supportive of the players," Atsu told the BBC.
"I was really happy because he got all the players involved in matches.
"That is difficult for most managers to do.
"However, he made sure each and every player had a part to play and everyone is really happy at that.”
Atsu joined Newcastle on a season-long loan from Chelsea last year.
The 25-year-old has made 30 league appearances involving 13 starts so far, with two matches to wrap up the season.
The Black Star has also assisted three goals, scoring four himself.
Meanwhile, latest media reports say Chelsea have given Newcastle up to a week after the season to cough up £6.5 million for the Ghanaian if the latter intend to secure the winger on a permanent deal.