Worcester are now only a point off the bottom of the Guinness Premiership after Leeds' win over Sale and the Warriors' 37-13 defeat to Bath.
Worcester flanker Tom Wood was sent off in the 62nd minute following his second yellow-card offence, and Bath coasted to a five-point maximum by scoring three tries after he departed.
Joe Maddock's first-half double was backed up by touchdowns for his fellow wing Matt Banahan, scrum-half Michael Claassens and substitute back-row forward Jonny Faamatuainu, while centre Ryan Davis booted three conversions and two penalties.
Fly-half Willie Walker bagged all of Worcester's points - a try, the ensuing conversion and two penalties - but the Warriors remain deep in relegation trouble.
They are just one point above bottom club Leeds Carnegie, having gone almost five months without a league win and 10 months since recording a Premiership triumph on the road.
It means their six-season stay in English rugby's top flight is under huge threat, suggesting an April 25 trip to Leeds will assume huge significance.
Bath though, can head to title contenders Saracens next weekend knowing that another success would inch them closer towards an improbable play-off challenge following their early-season struggles.
Worcester showed one change from the side that secured a losing bonus point against title contenders Saracens at Wembley last weekend as hooker Aleki Lutui replaced Chris Fortey in a side that saw skipper Pat Sanderson make his 200th Premiership appearance.
Bath boss Steve Meehan also made a front-row switch, handing prop David Flatman a start instead of David Barnes, although most attention revolved around 23 times-capped Barkley's appearance on the bench.
But it was underdogs Worcester who made the brighter start amid a pedestrian opening when Walker pounced for an 18th-minute try.
Bath centre Shontayne Hape had been fortunate to avoid conceding a penalty following a questionable tackle on his opposite number Dale Rasmussen, yet Worcester's forwards had no intention of letting their opponents off the hook.
Impressive close-quarter work punched into the heart of Bath's defence before Walker crashed through a weak tackle by home skipper Claassens for a try that he also converted.
The score briefly stirred Bath into action, and an angled run by fly-half Butch James enabled Maddock to finish neatly in the corner.
It was the cue for a six-minute purple patch by the New Zealander, who struck again following more good work from James after a Walker penalty took Worcester 10-5 ahead.
James' sweet inside pass found Maddock at full pace, and he easily skipped around Warriors full-back Chris Latham to post his second successive Premiership try double.
Davis converted and then kicked a penalty as Bath began to assert their authority, taking a 15-10 interval advantage after Wood was sin-binned for a technical infringement.
Bath were eager to make their temporary one-man advantage count, and they began the second period hotly in pursuit of a third try as full-back Nick Abendanon launched a long range counter-attack.
But the home side then lost James with what appeared to be a shoulder injury in only his third game since recovering from knee reconstruction surgery.
It meant Barkley, who suffered a broken leg during pre-season training last summer, featuring for the final 30 minutes at inside centre with Davis moving to fly-half.
Worcester though, continued to be architects of their own downfall, and Latham collected Warriors' second yellow card following a blatant body-check on Maddock.
Australian Latham, clearly aggrieved by his sin-binning, engaged in verbal banter with the crowd as Davis punished his indiscretion by kicking the resulting penalty before Walker pegged Worcester's arrears back to five points.
But Worcester then subsided, with Wood being sent off on receipt of his second yellow card after he appeared to elbow Bath lock Peter Short, before Claassens scored a close-range try that Davis improved.
The Warriors, despite England prop Matt Mullan's introduction as a substitute, were in disarray, and Banahan crashed over to compound their misery.
Faamatuainu then completed the second-half demolition job, leaving Worcester boss Mike Ruddock to pick up the pieces before next Friday's crucial home clash against Newcastle.
Tries:Maddock 2, Claassens, Banahan, Fa'amatuainu
Cons: Davis 3
Pens: Davis 2
Pens: Walker 2
Bath: 15 Nick Abendanon, 14 Joe Maddock, 13 Shontayne Hape, 12 Ryan Davis, 11 Matt Banahan, 10 Butch James, 9 Michael Claassens (c), 8 Luke Watson, 7 Julian Salvi, 6 Ben Skirving, 5 Peter Short, 4 Stuart Hooper, 3 Duncan Bell, 2 Lee Mears, 1 David Flatman.
Replacements: 16 Pieter Dixon, 17 David Barnes, 18 David Wilson, 19 Scott Hobson, 20 Jonny Faamatuainu, 21 Mike Baxter, 22 Olly Barkley, 23 Jack Cuthbert.
Worcester: 15 Chris Latham, 14 Chris Pennell, 13 Dale Rasmussen, 12 Sam Tuitupou, 11 Miles Benjamin, 10 Willie Walker, 9 Jonny Arr, 8 Kai Horstmann, 7 Pat Sanderson (c), 6 Tom Wood, 5 Craig Gillies, 4 Greg Rawlinson, 3 Tevita Taumoepeau, 2 Aleki Lutui, 1 Adam Black.
Replacements: 16 Matt Mullan, 17 Chris Fortey, 18 Olivier Sourgens, 19 Graham Kitchener, 20 Chris Cracknell, 21 Ryan Powell, 22 Matthew Jones, 23 Alex Grove.
Referee: Tim Wigglesworth