Bath's unbeaten start to the season came to an end as Owen Williams kicked 17 points at Welford Road to give Leicester Tigers a 34-14 victory.
Brendon O'Connor crossed for Tigers' first try in the first half before second-half scores from Tom Youngs and Ed Slater demonstrated the hosts' return to a strong and physical forward display.
Semesa Rokoduguni and Tom Dunn got tries in either half for Bath who suffered their worst away defeat in Aviva Premiership Rugby since December 2012.
Owen Williams, back at fly-half for the Tigers, got the first points of the game after five minutes as the home side enjoyed much of the early pressure.
And O'Connor made that pressure pay with the game's first try after Mike Williams stole a Bath line-out near half way and Peter Betham made the decisive break.
Betham found support from Telusa Veainu whose offload was taken by O'Connor to barge his way over from close range.
Williams added three more points from the kicking tee after 20 minutes but Bath were right back in the game two minutes later when Rokoduguni got his fourth try of the season.
The Bath winger beat JP Pietersen to a George Ford up and under and had an almost free run to the line and Ford's successful conversion made it 11-7.
Ford's opposite number Williams had the final say of the first half with his third penalty as Tigers took a lead into half-time for the first time this season with the score at 14-7.
Tigers continued their strong forwards pack performance with a second try after 45 minutes as a penalty was kicked to touch and the driving maul from the line-out saw Tom Youngs cross the line.
Ford uncharacteristically missed a penalty six minutes later and was punished by two more Williams kicks from the tee as the fly-half stretched the lead to 27-14.
But Bath refused to roll over and shortly after Anthony Watson's acrobatic try-scoring effort was ruled out, Tom Dunn finished a clever short line-out move for Bath's second try.
Dunn had a short run to his first Aviva Premiership Rugby try of his career and after Ford's touchline conversion, Bath went in search of a losing bonus point at 27-14.
The Tigers had the final piece of action however as another driving maul from a five-metre line-out created another try scoring opportunity.
After a series of short pick and drives from the forwards it was second row Slater who managed to seal the victory by forcing his way over.
Replacement Freddie Burns drop kicked the conversion as Tigers went in search of a try bonus point but had to settle for a 34-14 victory that sees them return to the Aviva Premiership top four.