World Cup winner Dallaglio, who could make his first England appearance for more than 19 months in the RBS 6 Nations opener against Wales next weekend, was powerless to prevent an emphatic defeat.
He started the game at blindside flanker – offering a possible England selection insight – but then switched to number eight as Wasps targeted a win which could have seen them regain top spot in the Premiership.
However, Bath were in no mood to assist Dallaglio’s possible England recall following his decision to come out of international retirement, and they stung Wasps with tries by prop Duncan Bell, Samoan centre Eliota Fuimaono and fly-half Chris Malone.
Malone added three penalties and two conversions for an 18-point haul, while Wasps could only reply with an Ayoola Erinle try – converted by Alex King who also slotted two penalties – and substitute Jeremy Staunton booted a late penalty.
Heineken Cup quarter-finalists Bath recorded just their fourth league win of the season, and the first since toppling Worcester on Boxing Day, but it was achieved in such stylish fashion to suggest they could soon start rapidly climbing the table.
Bath handed a Premiership debut to Fuimaono, with Malone replacing injured fly-half Olly Barkley and Matt Stevens packing down at loosehead prop.
England head coach Andy Robinson was among a capacity Recreation Ground crowd, with 11 of his Six Nations squad starting a game he could have done without just seven days before the Twickenham clash against Wales.
Bath made all the early running, with Malone prominent, and it took the home side just six minutes to end a season-long run of failing to score a Premiership try at home.
Malone’s clever inside pass freed wing David Bory, and although the Wasps defence managed to haul him down, Bath’s forwards piled in and Bell was sent crashing over.
Malone added the conversion, but both sides were soon forced to use their bench as bloodied Bath flanker Michael Lipman was replaced by Gareth Delve and hooker Jonny Barrett took over from Raphael Ibanez.
Lipman, his nose and forehead bandaged, did not reappear, but Ibanez returned 10 minutes later, by which time Wasps – who had slotted a 13th-minute penalty – had almost moved ahead courtesy of a brilliant Stuart Abbott break.
Abbott, a strong candidate for an England call-up next Saturday, beat four Bath defenders on a weaving run deep into the home 22, and despite being eventually tackled, Abbott was impeded as he tried to free up possession and Bath centre Alex Crockett received a yellow card.
King made a hash of the resulting penalty chance, sending it wide from just 25 metres, and Malone showed him how it should be done by slotting a penalty on 29 minutes, hoisting Bath 10-3 ahead.
Wasps lost number eight John Hart with a suspected dislocated shoulder four minutes before half-time, prompting a back-row reshuffle as Dallaglio returned to his familiar position. Joe Worsley switched from openside to blindside flanker and Ireland’s Jonny O’Connor entered the fray.
Bath ended the half reduced to 14 men for a second time after referee David Rose sin-binned wing Andrew Higgins when he illegally thwarted a Wasps attack, and King’s second penalty made it 10-6 at the break.
Bath began the second period in identical fashion to the first, scoring a try inside seven minutes.
Bory’s strong running scattered the Wasps defence and skipper Steve Borthwick marked his 200th first-team appearance by cutting an incisive angle, allowing Fuimaono to touch down despite Dawson’s last-gasp tackle.
Malone hit the post with his conversion attempt, yet Wasps were rattled and Ibanez was fortunate to avoid a yellow card after the latest dust-up in an escalating series of skirmishes.
Reddan replaced Dawson in the 52nd-minute, and Bath moved further ahead five minutes later when flanker Andy Beattie did the hard yards, allowing Malone to stretch over, convert his own try and leave Wasps 16 points adrift.
Wasps responded through an 80-metre breakout score as Erinle eased past Delve, Bath’s last line of defence, although television replays revealed Erinle had put a foot in touch. King converted, setting up an intriguing final quarter with Wasps 22-13 behind.
But two further Malone penalties, either side of O’Connor being sin-binned, saw Bath home and left Wasps licking their wounds, despite the home team receiving a third yellow card when number eight Zak Feaunati departed.