In what was a reduced game, lasting 70 minutes played on an artifical pitch, Martinez took the opportunity to give his whole squad some game time.
Gomez dispatched the penalty confidently, when Ben Watson was brought down, the result signalled a solid start to pre season for the Latics.
Elsewhere the hero of the 2010/11 great escape, Hugo Rodallega completed his free transfer to Fulham, after failing to agree a deal with the Latics.
He is set to earn a reported £70,000 a week from the move, although his departure leaves the Latics somewhat short upfront.
Rumours are circulating that Irish striker Conor Sammon is set to join Championship side