The fullback struck late on to secure Inter an opening day win.
“Of course the most important thing is we took the three points. Compliments also to Lecce they defend very good, but I think we deserve the win today," Dumfries told Sky Italia.
“I think that last year we dropped too many points in this type of match, but we showed a lot of character today and deserved to win, as we were fighting to the last moment of the match."
“It's very important that he came back. He is a world class striker, I am happy he is in the squad," added Dumfries.