Brighton took a first half lead thanks to a well-taken strike from Leandro Trossard - his third of the season and first since November.
Villa however improved after the break and were saved once again by their best player Grealish. The 24-year-old, who missed a good chance in the first half, smacked home a fine finish beyond home keeper Maty Ryan with 15 minutes remaining. He has now scored in each of his last four games against Brighton in all competitions
The draw means Brighton are 14th in the Premier League, just three points above the drop zone, while Villa are third bottom on 22 points.
"He came back into the Premier League and there was expectation on him," said Ian Wright speaking on Match of the Day. "People were looking at him and he has proven to be the quality player that everyone knows he can be.
"The chance he missed in the first half, he did well and showed good strength but went a bit too far and couldn't get it on target. For the goal it was a beautiful ball in and it was just a beautiful finish on his weaker foot, a fantastic goal.
"There is a big push to get James Madison in for England, and I think Grealish should be starting to get that attention as well."
For Brighton it is just one win in eight and they once again look set for a nervy finish to the season.
Alan Shearer added, "I don't see huge differences from last season, but I do still think they will have enough to stay up."