The result left Leicester reeling, with manager Peter Taylor suffering calls for his head on the first day of the season.
Wanderers, tipped by many for relegation, became the first Premiership club to score in the new campaign when Kevin Nolan hit home after 15 minutes.
The midfielder scored again and Michael Ricketts and Per Frandsen also added goals to put the top flight new boys 4-0 up at half-time.
Leicester began the more brightly, with Matt Elliott going close from Muzzy Izzet's whipped cross.
Bolton, back after a three-year exile from the Premiership, were tested by a series of high balls sent into their penalty area.
But they withstood the brief Foxes flurry and delighted the 2,000 away supporters by taking the lead on the quarter-hour mark.
Frandsen's sliding right-footed cross was met by Nolan's looping header which cleared Tim Flowers and found the top left-hand corner of the net.
Less than 10 minutes later, Michael Ricketts muscled his way past Gary Rowett to rifle in a second goal.
Leicester had their share of possession but did little with it - and it was no surprise when Nolan claimed his second and Bolton's third after 41 minutes.
Frandsen's delicate free-kick was flicked on by Gudni Bergsson and then drilled home from close range by Nolan.
Leicester were desperate for the half-time whistle and a chance to regroup but Bolton had not yet finished their demolition job.
In the fourth minute of stoppage time, Frandsen, provider of two of Bolton's goals, turned scorer when he fired home a 20-yard freekick into the bottom right-hand corner of Flowers' net.
After the fireworks of the first half, the second 45 minutes was bound to be something of an anticlimax.
And so it proved with Leicester again unable to make any headway in the Bolton half.
The visitors, meanwhile, were happy to slow the tempo but there was still time for another Frandsen special.
With seven minutes left, Rowett's foul allowed the Dane to tee up another superb free-kick which left Flowers with no chance.
It sealed a triumphant return to the Premiership for the Trotters, who won the match at a canter.
The Foxes, meanwhile, left the field with their tails between their legs to the sound of booing from their supporters.
15 mins Nolan's opener
33 mins Ricketts strikes
41 mins Nolan at the double
45 mins Frandsen on half-time
83 mins Frandsen hits fifth
Man-of-the-match Frandsen added another after the break to complete Bolton's perfect start to the season.
Leicester: Flowers, Sinclair, Rowett, Elliott, Davidson, Impey, Savage, Wise, Izzet, Sturridge, Akinbiyi. Subs: Royce, Gunnlaugsson, Benjamin, Lewis, Marshall.
Bolton: Jaaskelainen, Barness, Bergsson, Whitlow, Charlton, Nolan, Warhurst, Frandsen, Gardner, Hansen, Ricketts. Subs: Banks, Pedersen, Holdsworth, Marshall, Southall.
Referee: R Styles (Waterlooville).