Andy Keogh's sixth minute header proved the difference between the sides as the Latics started slowly but improved in the second period.
The result spoiled Martinez's 'homecoming' to the DW Stadium as boss, as well as the Latics' 100 per cent record this season after they beat Villa on the opening day.
Martinez blamed their exertions at Villa Park and international duty for a sluggish start which handed the initiative to Wolves.
Demanding weekHe told Sky Sports: "Well I think we saw two different performances. In the first 20 minutes we didn't find that intensity in our play and probably we paid the price for what has been a very demanding week.
"Many players went away on international duty and it is a big day the first league game and probably the first 20 minutes we looked sloppy.
"Wolves were on top in that period - obviously they got a goal and they created a couple of chances.
"But then after that, the reaction in the second half I'm really, really pleased."