Defending champions Bayern Munich kicked off the new season with a 1-1 draw at Moenchengladbach on Friday and less than 24 hours later, Stuttgart ran riot against luckless Fuerth.
Japan midfielder opened the scoring in sweltering temperatures when the Stuttgart captain fired home from a tight angle on 30 minutes.
Home midfielder Atakan Karazor fell foul of the heat and was helped off early on with circulation problems.
His replacement Philipp Klement added Stuttgart's second when he hit the far corner on 36 minutes.
After the break, Stuttgart winger Borna Sosa claimed three assists from two superb crosses and a pin-point accurate corner.
Kempf claimed Stuttgart's third when he powered home Sosa's cross, six minutes before striker Hamadi Al Ghaddioui made it 4-0 with a header.
Sosa struck again when his corner was again home by Kempf, who out leapt the defence before Fuerth striker Jamie Leweling netted the visitor's late consolation goal.
The heavy win seems to come at a cost as Stuttgart had 17-year-old Dutch striker Mohamed Sankoh stretchered off in the second half.
The league's other new club Bochum also made a losing start in Germany's top flight, going down 1-0 at Wolfsburg.
Bochum played virtually the entire match with ten men after midfielder Robert Tesche was sent off after just four minutes for blocking a shot with his hand.
Wolfsburg striker Wout Weghorst squandered the resulting penalty as his weak shot was saved, but the Dutchmen made amends with the winner on 22 minutes.
Hoffenheim grabbed the heaviest away win of the day by routing Augsburg 4-0.
Forwards Jacob Bruun Larsen and Sargis Adamyan put Hoffenheim 2-0 up before French teenager Georginio Rutter came on to grab the third, then set up Sebastian Rudy for the visitors' fourth.
Union Berlin started their season with a 1-1 draw at home to Bayer Leverkusen with both goals coming in the opening 12 minutes.
Nigeria striker Taiwo Awoniyi put Union ahead with seven minutes played only for Leverkusen winger Moussa Diaby to equalise five minutes later.
Star striker Erling Braut Haaland, who claimed a hat-trick in the German Cup last weekend, spearheads the Borussia Dortmund attack later at home to Eintracht Frankfurt.