Danny Gabbidon fired the Eagles ahead in the 26th minute with Andy King levelling matters 11 minutes later.
Stephen Dobbie restored Palace's lead midway through the second half, before Chris Wood made it two apiece 18 minutes from time.
Pearson said: "We were unlucky not to win it.
"I think we were the better side. We had to deal with a Palace side who made quite a few changes and adopted a different style.
"But I think for the most part we coped with that threat well and showed some resilience to come from a goal behind on a couple of occasions.
"We created a lot of decent chances and played some good football."