Ipswich's Zian Flemming scored in the final minutes after Palace had looked to have salvaged a point through Jørgen Strand Larsen, despite playing the majority of the game with ten players, after Axel Disasi was sent off.
Anan Khalaili opened the scoring with a superb strike early on, but Ipswich struck twice before half-time to get the lead in a see-saw contest.
“We are really frustrated because of the context of the game," Sage said in his post-match press conference after the game.
“We conceded with their [Ipswich's] first opportunity and the red card meant I had to re-organise the team in a 3-5-1. At the end of the game we came back into it by playing together.
“In the second-half we came back with more possession. We created chances and had the ball, and we got back to 2-2.
“We had the opportunity for the 3-2 but we missed it. And then at the end it’s really hard to concede in this manner.