Goals from Arouna Kone, James McArthur and Callum McManaman gave the Latics a vital win that closes the gap on 17th placed Sunderland to just two points with three games remaining.
"If anything was tested today it was the strong mentality of a very determined side who know exactly what they are doing and keep going till the end," the Spaniard told Sky Sports.
"When you come to a place like here you know the home team is very well organised and they work very hard to keep a clean sheet, so to be able to get three goals from open play and come from behind twice is due to the character, determination and an incredible, incredible mental strength in the dressing room."
With the prospect of an FA Cup final against Manchester City and Europa League football next season there is plenty to get excited about for Latics fans and Martinez believes the club can move to a new level next year if they secure safety - something he equates to winning the title.
"Eight consecutive seasons at this level is an incredible journey and we are fighting to reach our title - our title is staying up," he added.
"Today the performance was equal to the last three games but we got the three deserved points and that pleases me a lot as in football when you don't get the result you sometimes drop your standards.
"But that wasn't going to happen today. The players had a clear focus and a clear concentration on what we had to do to get the three points at a very difficult place.
"With the European qualification that we have next season we can get into new ground, break into different levels and one day we should be able to move the aim of avoiding relegation into trying to finish in the top 10.
"But where we are now is such an exciting time for us with three games to go in the league and being involved a major trophy.
"It is something to be very excited about."