City produced arguably their finest display in European competition under Pellegrini to seal their progression to the knockout phase, with Raheem Sterling, Fernandinho and Wilfried Bony on the score sheet.
For Navas, the match represented a reunion with the supporters he spent a decade playing for before his move to Manchester in 2013.
"The Sevilla supporters were incredible and I'm really grateful for the way they welcomed me back," Navas told UEFA.com .
"I felt really emotional and proud to see how much they love me. It was strange facing my old team after so many years."
Sevilla midfielder Grzegorz Krychowiak, meanwhile, was frustrated by his side's failure to reward the fans at the Ramon Sanchez Pizjuan with a victory.
"City were very strong," he said. "Our team has quality, but we haven't proved it and that's why we lost the game.
"We are still lacking in many aspects. Our fans made the effort the Champions League demands, but we didn't."