Having condemned Hull to relegation from the Premier League yesterday with a 2-2 draw at the DW Stadium, the Latics could now have a major say in the title race when they travel to Stamford Bridge on Sunday.
Wigan have already beaten the Blues at home this term and Martinez believes his players can pull off another shock against the table-toppers, something second-placed United will certainly be hoping is the case.
However, the Latics boss has stressed that his team - who secured top-flight survival over a week ago - will not be motivated by the prospect of doing their north-west neighbours a favour.
"It is not that Wigan Athletic is going to play for Manchester United. We will play for the good of football and for ourselves," Martinez said.
"It is a unique experience to go to Stamford Bridge having the world of football watching.
"We have got nothing to lose, but I can guarantee you that there is a belief in the squad that on the day we can compete with anyone, and that is the approach we are going to have.
"We are going to go to Stamford Bridge to try to win the game."
Wigan will be without key players in Chris Kirkland and Titus Bramble, who both missed yesterday's match, along with Charles N'Zogbia and Marcelo Moreno.
On the whole, their replacements performed well, with Jordi Gomez looking lively in midfield, striker Victor Moses scoring a fine opening goal and defender Steven Gohouri firing home a spectacular stoppage-time equaliser in front of watching Ivory Coast manager Sven-Goran Eriksson.
Goalkeeper Vladimir Stojkovic had a more difficult time of it in goal though, looking nervous throughout.
The Serbia international's punch had a role in Will Atkinson's first-half leveller for Hull, he was also slow to react as the Tigers scored their second through Mark Cullen and at one point, he was ironically cheered by the home supporters for catching the ball.
Martinez admitted Stojkovic was still coming to terms with English football.
"We all know that Chris Kirkland is one of the best English goalkeepers in the league, and someone you are going to miss when he is not there," Martinez said.
"But Vladimir is number one for Serbia, an international goalkeeper who will play in the World Cup.
"It is quite clear he has a different style of goalkeeping and he is still settling in.
"It doesn't help when you don't get many minutes to adapt, but I'm sure that we'll see him playing in the World Cup and we will see the stature of the goalkeeper that he is."
Martinez confirmed the season was over for Kirkland and Bramble, who have had surgery for finger and ankle problems respectively, and the same applies to Moreno due to the calf injury that forced him off last week against West Ham.
But the manager remains hopeful N'Zogbia, who has had stitches after cutting his foot, will be available for the trip to Stamford Bridge and rates the Frenchman's chances as "50-50".
Meanwhile, midfielder Paul Scharner - who came off the bench yesterday with 'THANX' dyed into his hair before providing the assist for Gohouri's goal - has confirmed that he expects to leave Wigan this summer.
"This was the last game at the DW Stadium for me, that's true - as a Wigan player," Scharner said.
"Next season, I am looking for a midfield position but it's too early to say at which club. I am looking to stay in the Premier League."
Wigan have also announced that chief executive Brenda Spencer will be retiring at the end of July after 24 years with the Latics.