The French team snatched a last-gasp 1-0 victory in the Champions League thanks to an Andre Ayew header.
"It's difficult to analyse the game, but as I expected, Inter are in considerably better shape than what we saw recently in Serie A," said Deschamps.
"We are happy with Ayew's goal, but also know the second leg will be tough. We need a great performance at San Siro and Inter will do everything to go through.
"With determination, we were able to get this gift at the end of the match."