The Barcelona coach lamented the dropped points in Europe - their second draw in succession - but praised Lionel Messi for getting in "the thick of the action"
Lionel Messi secured a point for the Blaugrana with a first-half equaliser after Robinho's opener to avoid a replica of last season's Champions League loss on Rossoneri turf.
The Camp Nou coach was pleased with Messi's contribution but lamented his side's failure to prevent Massimiliano Allegri's men from scoring and bemoaned the defensive nature of the Italian opposition.
"We dropped two points and deserved to win this game against Milan," Martino told Sky Sports.
"We created more scoring opportunities and that is why we would’ve deserved the victory. We made a mistake leaving the initiative to the Rossoneri when Milan scored their goal. We paid for that error.
"Messi played well, as did the rest of the team. He was in the thick of the action.
"It is not easy to play with so many opponents in their own half. We had the chances to score and it’s just a shame we didn’t make the most of them.
"The Clasico follows two consecutive draws but, from a performance point of view, I think we're in a good position."
Barca sit top of Group H on seven points - six points clear of Ajax, four points ahead of Celtic and two points in front of Milan - with three games to go.
The Catalans' next clash is against Real Madrid on Saturday, with kick-off at Camp Nou at 17:00BST.