Four tries before half-time gave Wasps the perfect platform for a big win and they eventually ran out 71-7 victors to remain in fifth place.
The hosts, who are moving to Coventry next month, made a fast start with tries from Nathan Hughes and Ashley Johnson inside the first five minutes.
That set a depressing tone for Welsh, who slipped to a seventh successive league loss to start the season.
Christian Wade and Johnson both scored hat-tricks, the former's tries all coming in the second half, while three other players also got on the scoresheet to resign the visitors to their heaviest defeat so far.
At the top of the table Exeter Chiefs moved within two points of the summit with a 24-18 victory over leaders Northampton Saints.
A free-flowing first half from Exeter gave them a 21-6 advantage that they never relinquished, Thomas Waldrom's double a particular highlight.
Waldrom showed excellent anticipation to intercept a Stephen Myler pass and race in for his first try on 29 minutes, before doubling his tally just before half-time when breaking free from the back of a scrum to cross the line.
Tom Stephenson and Jamie Elliott led a Northampton comeback in the second half with tries, but they were unable to reel their opponents in, falling to only a second defeat of the season.
Bath joined Exeter on 24 points following a 23-14 victory over Newcastle Falcons at the Recreation Ground.
Gavin Henson shone for the hosts with 13 points, while Stuart Hooper and Jonathan Joseph scored tries in either half.
Saracens are the third side on 24 points after the opening seven matches following a penalty-laden 21-21 draw with Leicester Tigers.
Charlie Hodgson and Owen Williams scored the only points of the game at Welford Road, the pair exchanging penalties through a tight 80 minutes.
Hodgson kicked four in the first half to give Saracens a 12-6 lead, yet Williams responded after the break to leave the match tied with 10 minutes to play.
A 74th-minute effort from Hodgson appeared to have given the visitors the win but, with the final kick of the game, Williams earned his side a share of the points.
Sale Sharks moved up to seventh with a 36-8 triumph against London Irish, while Harlequins are just above them following theiir 22-15 victory over Gloucester.