Palace moved up to 14th in the Premier League table after Ismaïla Sarr's penalty kick just before half-time earned them a point at the City Ground.
Forest had led through Morgan Gibbs-White's early strike, but with Neco Williams sent off for a handball leading to Sarr's penalty, the hosts retreated to a defensive shape in the second-half and frustrated the Eagles.
Glasner told Sky Sports: "I'm really pleased with the first-half, especially the reaction after going 1-0 down.
"We played a fantastic first-half. We controlled the game for the first 10-15 minutes in the second-half but then we lost our nerve.
"I could see the effort and I learned to respect the point when I first came here [to the Premier League]."
Palace did enjoy large swathes of possession after the break. But breaking down Forest proved a tough ask, with most of Palace's shots coming from outside of the penalty area.
