Speaking about the game to the club's official website, Martinez said: "From a football point-of-view you cannot explain how the game has finished in a draw.
"We did everything we had to do in limiting a counter-attacking side to very little and opened up a strong defensive unit time after time.
"We put the ball in good positions, looked a real threat in the final third and it was difficult to understand how we got to half-time with nothing to show for our dominance.
"We carried on with the same attitude and finally got the goal we deserved, but then fell into a feeling where we had something to lose and conceded a soft goal.
"So there's a feeling of frustration after the game and it's really a footballing injustice because the players deserved the win, the played as winners."
Next up for the Latics is the difficult trip to Anfield to face Liverpool on saturday afternoon.
