Leicester responded to former boss Gary Megson's exit in style thanks to goals from Collins John and Patrick Kisnorbo.
Brian Howard headed narrowly wide for the visitors before John prodded home following an Alan Sheehan free-kick.
Sheehan's corner provided the second for Kisnorbo but Marton Fulop needed to save well to deny Kayode Odejayi.
Barnsley continued to play the more attractive football but Foxes striker Matty Fryatt came closest to scoring with a looping header which went wide.
Leicester caretaker boss Frank Burrows on his hopes of succeeding Gary Megson on a permanent basis:
"What's not to like about being manager of Leicester City? We've got a fabulous stadium and facilities and we are determined to get back into the Premier League.
"Gary said they were happy with the staff at Bolton and he won't be taking me with him. I've told the chairman that I won't go anywhere as long as he wants me.
"I'm under contract here and I've told the chairman that I'll run the football team until he tells me different."
Barnsley boss Simon Davey:
"It wasn't the best of times to come to Leicester. When a manager leaves you're always looking for a reaction.
"When I took over as caretaker last year we won 2-0 against Ipswich and it can inject a fresh impetus.
"The supporters and everyone at the club came together and made it a cauldron. They got behind their team and that was a factor."
Leicester: Fulop, N'Gotty, Kisnorbo, McAuley, Stearman, Hume, Wesolowski (Chambers 42), Newton, Sheehan, John (Cort 73), Fryatt.
Subs Not Used: Henderson, Campbell, Porter.
Booked: Sheehan, John.
Goals: John 22, Kisnorbo 30.
Barnsley: Muller, Foster, Souza, Nyatanga, Kozluk, Devaney, Togwell (McCann 85), Howard, Campbell-Ryce (Ricketts 71), Mostto (Christensen 63), Odejayi.
Subs Not Used: Colgan, Werling.
Booked: Togwell, Campbell-Ryce.
Ref: Jarnail Singh (Middlesex).