Bath inflicted a first defeat of the new season on Aviva Premiership champions Leicester as former Tigers player George Ford guided Gary Gold's men to a 27-20 victory.
Ford, an ex-world junior player of the year who quit Welford Road this summer, kicked five penalties and converted centre Jonathan Joseph's first-half interception try.
Matt Banahan also scored before the break, giving Bath a commanding 18-point interval advantage after Tigers were briefly reduced to 13 men when front-row forwards Tom Youngs and Logovi'i Mulipola received yellow cards.
Leicester, though, displayed admirable character and they fought back brilliantly through second-half tries by Steve Mafi, Ed Slater and Vereniki Goneva that ultimately secured a losing bonus point.
It ensured a pulsating climax in the 100th-year anniversary fixture between two of English rugby's fiercest rivals, but Bath did enough to make it two wins from two after they triumphed at Newcastle last week.
Exeter Chiefs bounced back to winning ways at Sandy Park as they overcame London Wasps 30-26 to send the visitors to their ninth successive defeat in all competitions.
The Devon side, who suffered their largest Premiership defeat at Northampton Saints last time out, went inside at the break with a 16-12 lead after wing Tom James crossed for the only try of the opening 40 minutes.
Fly-half Gareth Steenson converted and added three penalties while Andy Goode replied with four penalties of his own for Wasps.
The Chiefs scored two further tries in the second half through flanker James Scaysbrook and a second from James, converted by Steenson.
But Wasps kept battling with tries from wing Christian Wade and flanker Ashley Johnson both converted by Goode.
A late Ian Humphreys penalty secured a barely-deserved 20-18 victory for London Irish at Worcester.
The Exiles won just once away in the Premiership last season but some late ill-discipline from the hosts ensured they were able to immediately get off the mark this term on their travels.
Marland Yarde scored a pair of tries but it was Humphreys who was the matchwinner with four minutes left after Ed Shervington was penalised.
David Lemi and Ignacio Mieres scored the Warriors' two tries with the Argentinian adding eight points from his boot.
Worcester were left with only themselves to blame for defeat after they had been the better side but failed to take their chances, especially in the absence of the yellow-carded Chris Hala'ufia.
The Warriors failed to score in his absence at the end of the first half before seeing Yarde touch down to level matters at 10-10 at half-time.
Irish only had two significant chances to score tries in the whole match but Yarde made the most of both to pave the way for a morale-boosting win.