And Rangers manager Ian Holloway was further infuriated by referee Phil Dowd after seeing the official disallow two Martin Rowlands goals for fouls.
Leicester were glad to put 2004 behind them, a year which saw them win just four games at the Walkers Stadium.
They got off to just the start they wanted courtesy of David Connolly's controversial penalty after eight minutes.
Connolly burst into the box was challenged by Richard Edghill and Daniel Shittu and went over and the referee blew for a penalty - not for a foul but for a handball by Shittu.
Connolly waited until the protests had subsided before calmly dispatching the spot-kick low to the keeper's right.
Stuart Taylor kept City's lead intact on 22 minutes with a superb diving save after Kevin McLeod touched a free-kick to Paul Furlong who drove a 25-yard shot through the defensive wall.
Leicester then went close to doubling their lead when James Scowcroft headed narrowly over and Lilian Nalis headed a good chance straight at the keeper from eight yards.
After Rangers had seen a Rowlands goal disallowed for pushing they missed a great chance to level on 37 minutes when Georges Santos found himself on his own six yards from goal.
The defender seemed certain to score, but he shot straight at Taylor's legs with the ball ballooning over the bar.
After the restart Leicester went close on 54 minutes when substitute Joey Gudjonsson broke clear and fired in an angled shot with Chris Day did well to palm away.
QPR were furious on the hour mark when Rowlands had a second goal ruled out for a push, but undeterred they continued to lay siege to the home goal and were denied an equaliser when Adam Miller let fly from 25 yards with Taylor leaping across his goal to claw the ball away.
And the keeper came to City's rescue again on 70 minutes, this time blocking Shittu's angled drive at the near post.
Then in time added on Rangers have one final chance, when following a goalmouth scramble, Shittu fired a loose ball just wide from 12 yards.