Wigan clinched a stoppage-time victory to put an end to a six-match away losing streak.
"I'm not going to lie, that's a massive result for us," Martinez said. "If you don't get results, it's impossible to get confidence and momentum.
"In the last two games, we've played without the fear of being on an eight-game losing run and that's a credit to the players.
"It's a merry go round. One week it's me [under pressure], the next it's Andre Villas-Boas, then it's Steve Bruce. It just goes round."
Wigan are 19th in the Premier League with nine points from 13 games.