Despite falling behind to an early Facundo Buonanotte strike, Thomas Frank's men responded ruthlessly through Yoane Wissa and the scintillating Schade, as the Bees won four top-flight home games in a row for the first time in the Premier League era.
An early wonder save from Mads Hermansen would ostensibly be a sign of things to come for the visitors, or so some may have thought, as the Foxes surprisingly struck first through Buonanotte after some brilliant strength from Jamie Vardy.
However, Ben Dawson's side had only poked the Brentford bear, as Wissa levelled matters within four minutes before Schade propelled the Bees ahead with another four moments gone, albeit while Leicester had 10 players on the pitch with Caleb Okoli receiving treatment.
Okoli eventually had to make way soon after, but his replacement Jannik Vestergaard was powerless to prevent the on-song Schade from making it three deep into first-half injury time, continuing the Gtech goals galore theme.
Any doubt over the West London outcome was more or less extinguished when Schade registered his first-ever senior career treble on the stroke of the hour mark, giving incoming Leicester boss Ruud van Nistelrooy plenty to ponder as he watched on helplessly from the stands.
As Brentford continue to sparkle at home, they have temporarily shot up four places to seventh in the Premier League table, while 16th-placed Leicester are still just one point clear of the relegation zone.
BRENTFORD VS. LEICESTER HIGHLIGHTS
Facundo Buonanotte goal vs. Brentford (21st min, Brentford 0-1 Leicester)
The post-Cooper era at Leicester kicks off on the right foot!
Jordan Ayew threads a perfectly-weighted through ball down the left channel to Jamie Vardy, who is on the way down after a shoulder-to-shoulder with Ethan Pinnock but manages to hook the ball to Buonanotte for a tap-in before he hits the deck.
Yoane Wissa goal vs. Leicester (25th min, Brentford 1-1 Leicester)
Immediate redemption for the men in red and white, and after Leicester struck thanks to an attack down the left, Brentford have taken a leaf out of the Foxes' book!
Schade is released by a slick ball from Mikkel Damsgaard, and the German wastes no time in delivering a first-time low cross for Wissa to prod home.
Kevin Schade goal vs. Leicester (29th min, Brentford 2-1 Leicester)
From provider to goalscorer in the blink of an eye! Schade turns the tide for Brentford at the end of a mad-cap eight minutes, as the hosts capitalise on Okoli's injury momentarily reducing Leicester to 10.
Brentford's makeshift left-back Keane Lewis-Potter surges forward from the back and picks out Wissa to help the ball on to Bryan Mbeumo, whose ball in is deflected into the path of Schade to fire low into the net.
Kevin Schade goal vs. Leicester (45+8 min, Brentford 3-1 Leicester)
Plenty of food for thought for Van Nistelrooy at the end of a chaotic first half.
James Justin just steps out of his defensive position for a split second, allowing Damsgaard a yard to find Schade just inside the box, and the 23-year-old coolly lifts the ball over Hermansen from a tight angle for his second.
Kevin Schade goal vs. Leicester (59th min, Brentford 4-1 Leicester)
A first-ever senior career hat-trick for Brentford's glistening German!
Like a knife through butter, Nathan Collins takes out the permeable Leicester backline with a terrific weighted pass through to Schade, who takes one touch before calmly finding the bottom corner with his left foot. Three points in the bag, three goals in the bag, match ball in the bag.
MAN OF THE MATCH - KEVIN SCHADE
The first German to score a hat-trick in the Premier League since Andre Schurrle in 2014 - and just the fourth from his nation to do so overall - Schade taught Leicester a merciless lesson in how to be ruthless in front of goal.
Showcasing his array of finishes with low strikes and a delicate dink, as well as his assist for Wissa, the ex-Freiburg man doubled his total Brentford goal tally in just 59 minutes against the Foxes and has given Frank yet another welcome dilemma in the final third.
BRENTFORD VS. LEICESTER MATCH STATS
Possession: Brentford 60%-40% Leicester
Shots: Brentford 13-7 Leicester
Shots on target: Brentford 6-3 Leicester
Corners: Brentford 5-4 Leicester
Fouls: Brentford 9-10 Leicester
BEST STATS
WHAT NEXT?
Both camps only have a few days to recuperate before going again in midweek, as Brentford pit their wits against Aston Villa at Villa Park on Wednesday evening.
Meanwhile, Van Nistelrooy manages his first Leicester game 24 hours beforehand, as the Foxes host West Ham United at the King Power Stadium on Tuesday.