Teenager Mario Balotelli, who had spent much of the season in Inter Milan coach Jose Mourinho's doghouse, scored twice and Hernan Crespo added the equalizer in the 77th minute.
Roma had gone ahead on first-half goals from Daniele De Rossi and John Arne Riise, and Matteo Brighi made it 3-1.
Balotelli was starting because star Zlatan Ibrahimovic is sidelined with a muscle problem.
"A point is gold from a match like this," Mourinho said. "The match seemed lost at 3-1. My team deserves this point, not for the quality of play. Their character made the difference."
Juventus beat Napoli, 1-0, at home thanks to Claudio Marchisio's goal on Saturday.
Third-place AC Milan's troubles continued when it lost, 2-1, at Sampdoria. The loss followed its elimination from the UEFA Cup that put Coach Carlo Ancelotti's job under threat.
"We are conceding goals too easily," Ancelotti said. "We found ourselves 2-0 down even though we had played more or less as well as Sampdoria. It is a delicate moment that must pass and we must make it pass with the least damage possible.
David Beckham, on loan from the Los Angeles Galaxy, was replaced in th 68th minute of AC Milan's loss to Sampdoria that loosened its grip on third-place -- a finish at which earns a Champions League spot.