But Nigel Pearson's side have not lost at home in over a year and fought back to deservedly claim a point when Matty Fryatt scored a spot-kick of their own.
Both sides were promoted from League One last May, with the Foxes beating Posh to the title.
And while Leicester have settled into life back in the second tier well, Ferguson's side have now equalled a club record for the most games without a win at the start of a season.
Posh went seven games without a win at the beginning of the 1988-89 season and have now matched that despite playing some fine football during the opening period.
The visitors made all the early running with Boyd looking lively and should have taken the lead when midfielder Lee Frecklington shot narrowly wide.
Aaron Mclean was giving Leicester centre-back Wayne Brown a torrid time and won a penalty in the 32nd minute when he turned Brown and the veteran shoved him to the deck.
Boyd stepped up and steered his left-footed strike confidently into the corner.
The lead was thoroughly deserved but the goal kick-started Leicester into belated life.
Steve Howard had a header cleared off the line within seconds of the restart as the home crowd vented their frustration and Fryatt then incredibly shot wide when clean through on goal.
Forward Paul Gallagher was then twice denied by goalkeeper Joe Lewis in the closing seconds of the first half before Pearson replaced Brown at the break.
Aleksandar Tunchev and Andy King came on as Pearson changed the shape of his side and the changes reaped instant benefit when Fryatt scored from the penalty spot in the 49th minute.
Fryatt beat the offside trap and found Gallagher in space on the penalty spot where he produced a wonderful deft chip which beat Lewis but hit the crossbar.
Right-back Robbie Neilson reacted first to put the ball back across the goal where Tom Williams was adjudged to have blocked with his hand and referee Russell Booth pointed to the spot.
Fryatt confidently dispatched the kick low into the corner for his sixth goal of the season.
Steve Howard and Gallagher were both guilty of poor efforts as the Foxes pushed forward in search of a winner while Craig Mackail-Smith cracked a 20-yard volley inches wide at the other end.
But neither attack could match the intensity of the opening period and the game petered out into a draw.