Set-piece goals from Sylvan Ebanks-Blake and former Fox Richard Stearman left City with a second-half mountain to climb against Stale Solbakken’s men.
And despite a much improved second-half performance and a spectacular goal from Paul Konchesky, the Foxes ran out of time to peg back their Midlands rivals, slipping to their third 2-1 defeat in as many away league games this season.
“It’s a recurring theme unfortunately,” Pearson admitted after the game.
“We’ve conceded two poor goals from set-pieces and it’s annoying because that was always going to be one of their main opportunities.
“Again, second half, we were much better. We had to throw caution to the wind at times but I felt we created a lot of goal-scoring chances again.
“In the first half I didn’t think we worked hard enough when we had the ball, which meant the player in possession became isolated. You have to work incredibly hard in both directions and utilise the players you’ve got.
“It was a tough afternoon, but the things that displease me are not when players are working exceptionally hard and are not quite on top. The things that let us down today were a lack of concentration and acceptance of responsibility to do a job from defending.
“It’s frustrating and it’s a recurring theme that we must put right.”
City will now look to regroup quickly ahead of two home games in the next seven days, with Burnley the visitors on Wednesday night and Hull City travelling to King Power Stadium next Sunday.
Wales international midfielder Andy King could be a doubt for the game after being withdrawn during the first half at Molineux with a hamstring problem.
“We need to look at who is available for the midweek game, but we have other players that will be available,” Pearson added.
"Andy felt his hamstring. We’re not sure at the moment, we’ll have to see how it is. He said straight away that he felt it but we’re not sure if it’s a pull. We’ll see tomorrow.
“We’ll get it right. I think throughout the course of the season we have played three league games away and had three defeats, which has been a bit tough on how we have performed, but you can’t give teams two-goal starts.