The Bluebirds grabbed an injury-time leveller through substitute Rudy Gestede to cancel out Michael Keane's opener, denying the Foxes three massive points in the battle for promotion.
Pearson said: "We deserved to win the game as we were much the better side.
"It was a bit cruel on the players bearing in mind how late it was. This is never an easy place to come to and a bit of confidence has been lacking. But I thought we played very well.
"We know that our points tally of late has not been good enough and we've fallen off the pace. I just feel for the players.
"I can't remember Cardiff really creating a chance until the goal.
"It was fatigue, but that happens. I'm not going to get too downbeat about it. You've got to work your way and show courage through difficult periods. The players did that."