Following the departure of the prolific Shane Long to West Brom this week, more responsibility for goals rested on the shoulders of his Republic of Ireland international Noel Hunt and the Waterford man responded with the opener after 64 minutes.
The Royals wrapped up all three points in the final minute through substitute Hal Robson-Kanu.
Teenage striker Jeff Schlupp was rewarded for his Carling Cup hat-trick in midweek with a league debut for Leicester.
The Ghanaian-born Germany Under-19 international, along with goalkeeper Kasper Schmeichel and defenders Matt Mills and Paul Konchesky, was one of four survivors from the team that defeated Rotherham on Tuesday night as manager Sven-Goran Eriksson again made wholesale changes.
Former Fulham full-back John Pantsil was also handed his Foxes debut.
Reading's Carling Cup tie at Charlton was postponed due to the riots in London, so Royals boss Brian McDermott named largely the same side that began the season against Millwall last weekend.
The only change saw Mathieu Manset replace Long.
The visitors dominated a first half of few chances.
They should have taken the lead in the 28th minute but Alex Pearce somehow headed over from close range from Ian Harte's inswinging corner.
Before that, Manset broke clear on goal and shot narrowly wide from the edge of the box when perhaps a better option would have been to tee-up the arriving Hunt.
David Nugent had a couple of efforts for Leicester early on and late in the first half but neither worried Adam Federici in the Reading goal.
Eriksson's men returned for the second half a different side.
Nugent clipped the outside of the post with a curling shot from the left side of the area and Federici had to help a thunderous 20-yard shot from Andy King over the crossbar.
At the other end, Schmeichel saved from Jimmy Kebe with his feet.
Nugent continued to look lively and shot wide once more from the edge of the box.
Despite Leicester's improvement, Reading took the lead through Hunt's superb glancing header at the near post from Harte's driven corner.
Kebe came close to making it 2-0 soon afterwards following a mazy run down the right but he shot just wide.
Sol Bamba, a reported target for Blackburn, had a chance to equalise but the big defender could not direct his header on target.
Reading sealed their first victory of the season in the 90th minute with a stylish move down the right that culminated in Kebe setting up Robson-Kanu, who drove the ball into the top corner from 12 yards.