Although this may appear to have been a comfortable victory for the South Yorkshire side, Leicester only had themselves to blame for failing to return to the Walkers Stadium with all three points, let alone a draw.
Two of their debutants, Rab Douglas and Nils-Eric Johansson, conceded penalties, neither of which were conclusive, while they contrived to squander chance after glorious chance. Mark de Vries was the principal culprit, but David Connolly, otherwise outstanding, Jason Wilcox and Momo Sylla were hardly free from blame either.
Andy Gray, heavily linked with a move to Sunderland late last week, converted the first penalty before Connolly equalised early in the second half. Steve Kabba, part of a triple substitution from Neil Warnock, the United manager, dispatched the second spot-kick before Paul Ifill, on his debut, and Leigh Bromby gave the scoreline an entirely lopsided appearance late on.
"I'm a bit shell-shocked, to be honest," said Craig Levein, the Leicester manager. "I can't for the life of me understand how we lost that match. I thought we played well, and it might sound strange but I'm not too concerned. The game was decided by the referee awarding the second penalty."
United's opening goal, after 34 minutes, was certainly harsh on Leicester, who had started much the better. Douglas, the former Celtic goalkeeper, hesitated when favourite to beat Ifill to the ball. That allowed the winger to get the all-important first touch before the two tangled untidily and the penalty was awarded.
Leicester continued to press without reward for the remainder of the half, but five minutes after the break they did draw level. Joey Gudjonsson fed the sprightly Connolly, who turned inside Bromby before taking a shot which took a deflection off Jon Harley and squirmed into the bottom corner.
If there was an element of fortune involved, Leicester had earned it, and with De Vries becoming more involved, Connolly was able to take advantage of the space behind his strike partner.
Both men missed good opportunities, though De Vries was the more culpable. As chances continued to come and go, Sylla's volley screwed over the crossbar and the hapless De Vries slipped at the crucial moment with a clear sight of goal.
How they were punished. Warnock's growing frustration resulted in a triple substitution, and it proved an inspired move. That said, none of the three replacements were directly involved in the day's second penalty, harshly awarded for handball and scored by Kabba.
Another of the substitutes, Keith Gillespie, playing against his former club, delivered a trademark cross that Ifill met at the near post with a flashing header. Douglas then made a horrible job of dealing with Ifill's cross and Bromby bundled the ball in.
"It's nice to get a win on the first day," said Warnock. "We lost our shape at the start of the second half, and that was their best chance, but after the substitutions we deserved it."