West Ham United, reduced to 10 men for the final 23 minutes, held on for a goalless draw at Aston Villa in the Premier League on Monday.
The Hammers move up to eighth place with the point, while promoted Villa are now one spot above the relegation zone on four points from their opening five games.
Arthur Masuaku was sent off in the 67th minute after picking up a yellow card for a late challenge on Ahmed Elmohamady.
In a strange first-half incident, Villa's Anwar El Ghazi clashed heads with team mate Tyrone Mings as the pair remonstrated with each other but no action was taken by the referee.
Grealish played down that incident as "handbags" but conceded he should have done better with his opportunity.
"It was a mixed performance. In the first half, we were the better team and had the better chances. Maybe at the start of the second half too," he said.
"I feel like as they went down to 10 men, we tried to rush things and force things and give the ball away. We got worse when they went down to 10 men."
West Ham's England midfielder Declan Rice said the Londoners were content to have avoided defeat after going down a man away from home.
"We're very happy with the point," Rice said. "We were a bit slow in the first half and in the second half when we went down to 10 it was always going to be tough. We dug in and we were still creating chances, which was positive.
"When Arthur went off we really dug in. If this was the West Ham of last season we'd have lost this game."