Udinese midfielder Widmer earned a penalty against Milan and felt the Friulani deserved their Coppa Italia victory.
Mario Balotelli had given the Rossoneri an early lead, but Luis Muriel’s penalty and a Nico Lopez solo effort secured the 2-1 result at San Siro.
“We played a very good game, as we already had done against Inter,” he told Rai Sport. “We remained united, worked hard, threw our all into it and won the match.
“At the start we were a little tense, but after the goal we started playing the ball well and moving it round, so it was overall a good performance.
“We are still in a difficult moment and must take it one game at a time.”
Udinese have now knocked both Inter and Milan out of the Coppa Italia.
They will face the winners of Fiorentina-Siena in the semi-finals next month.