After floundering in the early parts of 2012, Massa scored points in all of the last 10 Grands Prix, helping Ferrari to secure second in the constructors' championship.
He also played a part in the drivers' championship, notably at Austin where, after outqualifying Alonso, he took a penalty to ensure the Spaniard started on the clean side of the grid.
Di Montezemolo hailed Massa's resurgence during Ferrari's Christmas celebrations, adding that it could also stand Ferrari in good shape next season.
"I don't know where you went in the first part of the year," di Montezemolo said to Massa, "but I am very pleased you came back.
"It meant we were able to finish ahead of major teams in the constructors' classification, but it is also important for next year."
Massa, who admitted the long-running uncertainty over his Ferrari future played a part in his poor early form, said his revival was good preparation for next year.
"This has been a very difficult year for me, especially at the start, when we couldn't find the right way to move forward with our car," he admitted.
"The second part was very different: I was more competitive and I managed to get back to the way I was before.
"Now I am more motivated than ever: the second part of the season was like a training session for next year."
Di Montezemolo added that it was imperative for Ferrari to be competitive from the first race next year, saying: "Fernando had an extraordinary season and I am sorry not to have given him a car that was quick as well as reliable.
"In 2013 the aim, not just for me but for all of you, is to immediately have a car that's capable of winning.
"We must all do a little bit more to achieve that, but without losing any of the plus points we demonstrated this year, starting with reliability.
"We can be pleased with the improvements we have made on the strategy front, at the pit stops and in our race preparation and we must maintain these strong points next year."