City failed to win any of their opening four matches in Europe's elite club competition this season, while patchy form in the Premier League saw the defending champions fall behind pacesetters Chelsea.
But a dramatic 3-2 victory over group winners Bayern Munich on matchday five in Group E has acted as a catalyst for Pellegrini's men, who had cut Chelsea's advantage to three points domestically before second-half goals from Samir Nasri and Pablo Zabaleta secured three points and the second qualification spot in the Italian capital.
"We did it in the same way we have been playing in the last three weeks," Pellegrini told Sky Sports after overseeing City's triumph at the Stadio Olimpico.
"We've recovered our normal performance - we are making good pressing, we are playing well with the ball.
"So I think we are similar to the team that won the title last year.
"We are a solid team and we are recovering the ball in the correct way, in the correct moment - all the team working together without the ball and after that all the team playing with the ball.
"Before this game I had a lot of trust in what we could do against Roma here.
"I talked with the players before the game. I think against Roma in Manchester we played the worst game of the season maybe.
"Playing the worst game of the season, we drew [1-1]. So we were absolutely sure that, playing the way we were playing the last three weeks, we would win today and we did."
City prevailed in Rome despite the absences of top scorer Sergio Aguero, captain Vincent Kompany and Yaya Toure, while David Silva only returned to action as a second-half substitute following more than a month on the sidelines with knee ligament damage.
Pellegrini paid tribute to a fine all-round team performance, which he felt countered suggestions that Aguero's sensational form this season has cast City as something of a one-man team.
"I said yesterday that I don't want to complain about the players who are not in our team," he added.
"You must decide to play without Kompany, without Yaya Toure, without Silva, without Aguero.
"It is difficult but you can play exactly the same without [those players].
"I think that this team deserves a little more credit than maybe the press always give us - because we are just Sergio but now Sergio is not playing, the team qualified and we played well in Europe the same way we do in the Premier League."
