The Terriers were left frustrated by the officials after last season’s top scorer touched in the ball after Mathias ‘Zanka’ Jorgensen had fired across goal only for the linesman to flag.
Replays clearly showed Andy King to be playing Kachunga offside, much to the annoyance of David Wagner.
Town took the lead inside 60 seconds of the second half, a delightful turn from Laurent Depoitre leaving Harry Maguire trailing.
The Belgian international then ran on before firing across Kasper Schmeichel into the corner of the net.
Leicester’s reply came just four minutes later, Andy King being tripped by Chris Lowe and referee Jon Moss rightly pointed to the spot. Jamie Vardy then opted for power from the spot and the Foxes were level.
David Wagner had been scathing about his side’s attacking play after the defeat at West Ham, accusing his players of looking nervous and making far too many unforced errors.
The Town chief had demanded a response and he got it, as Laurent Depoitre netted a goal on his full league debut to cap a much improved attacking display.
Everyone played their part, from Abdelhamid Sabiri on full debut with his assist for the opener to Tom Ince, who came oh so close to netting a late winner with a curled effort.
But for a wrongly raised offside flag, Elias Kachunga would have won the game for the hosts.