Martinez celebrated a precious win.
He said: "I am extremely, extremely proud because remember that football is a team game and how you approach a disappointment allows you to fulfil your potential.
"There were a few players disappointed because they were not in the starting line-up, but two of the subs when they came on, they were the ones who produced the goal.
"They showed great concentration and a great desire to help the team, and that's why we won today, because of those dynamics internally.
"I couldn't be prouder as a manager to have players who are disappointed because they want to play, but once they are on the pitch, they are only thinking unselfishly for the team and what they can do.
"Franco Di Santo's performance and James McArthur when they came on is probably the clear message I want, Wigan Athletic playing with that respect and with that enthusiasm. I am extremely proud of them."