The striker believes the Portuguese outfit could have netted another goal with a bit of luck, but was happy with the final result
The Colombia international helped his side to a vital 1-0 home win with his second-half goal, but he conceded that Porto struggled after the interval as Napoli threatened on several occasions.
"My goal was important for the team, but it was all about the hard work of the team. We did what the coach demanded from us and were pretty strong," Martinez told Sport TV.
"We played with the intensity that we wanted to show and that people are used to when they watch Porto. We could have scored another goal with a bit of luck.
"Then again, they could also have scored. We fought hard and put in a great performance. Napoli made life difficult for us, especially in the latter stages of the first half and after the break."
Both sides meet again at the Stadio San Paolo on March 20.