The heat is on Brendan Rodgers after Bournemouth staged a superb second-half comeback.
After Patson Daka's opener,Leicester looked in control but failed to respond to Bournemouth's response.
Ryan Christie touched in Dominic Solanke's knock-down five minutes later to complete the revival.
By the end of the game, the good feeling that had been created by Monday's win over Forest had dissipated.
In front of prospective new owner Bill Foley, Gary O'Neil has not lost a game in his five games as interim boss.
With just four points from their first nine games,Leicester are stuck in 19th place, while Bournemouth move up to 8th.
ScottParker lost his job as Bournemouth manager after stating publicly that the team needed new players.
This is the fifth game in a row that the Cherries have won under interim boss O'Neil.
O'Neil has brought stability and structure to this Cherries side and has also added resilience, shown first by a victory from two goals down and then here.
They lacked a cutting edge in the first half and were well marshalled by the Foxes, with only Ryan Fredericks' claims for a penalty to get excited about.
They were a different proposition after the break, pushing the Foxes back and equalising, even if Billing's fine finish was preceded by bad errors.
Bournemouth attacked again and Billing was given time to pick out Solanke who tucked away the ball.
Jaidon Anthony's late strike on the counter- attack was ruled out for an inaccuracy in the build-up to the game.
O'Neil should be part of the new era that is coming.
The victory over Forest seemed to mark a turning point for the club, but the old problems that led to six defeats in a row were still present.
Faes let Solanke in to set up Bournemouth's leveller and then they were too passive for the winner.
It has been a bad start to the season for Rodgers' side and the next two games at home to Crystal Palace and Elland Road may be crucial in deciding his future.