The Argnetine rose highest at the back post to convert Ilkay Gundogan's centre to put City back on level terms at the Stadio San Paolo.
The goal came following City's first real spell of pressure as they strangled back control after a good start from the hosts.
Perhaps unsurprisingly, it was Otamendi's first Champions League goal.
Check out the strike for yourself below:
Otamendi goal for #MCFC pic.twitter.com/8xx863UG0R #NAPMCI #UCL
— FootySays (@Footy_Says) 1 November 2017