The defender cancelled out Dries Mertens' opener in the last-16 second-leg clash with a strong header that proved to be too much for goalkeeper Pepe Reina early in the second half.
He found the net a second time just minutes later via a deflection off Mertens to effectively end Napoli's hopes of causing a surprise, although his second strike was eventually attributed to the Belgium international, with Alvaro Morata scoring late on as Madrid progressed 6-2 on aggregate.
It was not the first time this season that Ramos has come to Madrid's rescue, the centre-back netting a vital equaliser against Barcelona back in December.
Ramos also netted in Madrid's Champions League final triumphs in 2014 and 2016 and Navas is impressed with the 30-year-old's ability to find the net when it matters most.
"Ramos is a very important player, he is always there to help us out and we have got to be pleased with the result," Navas told Madrid's official website.
"He has got a striker's instinct within him, whenever he goes up for corners we have real belief in him and when it comes to headers, he has always got the ability to put the ball where he wants to."
Tuesday's strike saw Ramos take his tally for 2016-17 to nine goals in 28 appearances in all competitions, his most prolific season to date.