Gloucester hooker Darren Dawidiuk was sent off for a tip-tackle as Bath edged past their West Country rivals 31-25 in a thrilling Aviva Premiership derby at the Recreation Ground.
Former England captain Mike Tindall, making his 150th appearance for Gloucester since leaving Bath, roused his 14 men into thrilling fightback from 31-18 down, looking for the converted try that would snatch victory.
But Bath had too much control up front and celebrated a first Premiership victory over the Cherry and Whites for three seasons.
They were awarded a penalty try in the first half and followed up with further touchdowns from Tom Biggs and Kyle Eastmond. Fly-half Tom Heathcote kicked four penalties and two conversions.
Henry Trinder and Jonny May (2) scored the Gloucester tries with Freddie Burns converting one and Rob Cook adding two penalties and two conversions.