|London Welsh (10) 14|
|Cons: Roberts, Robinson Tries: Reynolds, Fonua|
|Bath (7) 29|
|Cons: Homer (2) Tries: Webber, Houston (2), Burgess, Fa'osiliva|
London Welsh were relegated from the Premiership as Bath ran in five tries to climb to third in the table.
Bath led 10-7 at the break with Rob Webber and Leroy Houston crossing for the visitors while Welsh responded through a Nic Reynolds converted try.
Sam Burgess scored Bath's third try after the break and Tom Homer kicked his first conversion of the match.
Houston and Alafoti Fa'osiliva added to the lead although Welsh at least had the final say with Opeti Fonua's try.
The defeat was Welsh's 18th straight loss in the Premiership as they make an immediate return to the Championship following their promotion last season.
It mirrors their fate in 2013, when they also lasted a single season in the top flight.
Bath, who close to within a point of Saracens as they chase a home tie in the play-offs, dominated early proceedings at a windswept Kassam Stadium with rain also making handling difficult.
Webber was first to cross, bundling over in the corner after a rolling maul from Bath but Homer failed to add the conversion. Soon after, Houston went over in the corner after a line-out went astray but the wind again disrupted Homer's conversion.
Welsh, who also lost Nathan Trevett to a yellow card before half-time, went into the break trailing by just three points with Reynolds going in under the posts.
Burgess scored Bath's third try, and only his second in rugby union, after the visiting team stole a Welsh throw at a line-out and with the wind behind him Homer kicked his first conversion for 17-7.
Houston scored his second try of the game with the number eight picking up from a scrum and forcing his way over as Bath earned a bonus point. An interception led to a fifth try soon after with Fa'osiliva the grateful recipient and Homer's conversion took the game further away to 29-7.
To their credit Welsh responded well to the set back and scored their second try of the game through Fonua with a catch and drive as Will Robinson's conversion made it 29-14.
There was a late yellow card for Dean Schofield but Bath were unable to add to their tally in the limited time remaining.
London Welsh head coach Rowland Phillips: "We had a lot of positives today and we will be looking to build on that performance.
"The club is too proud just to switch off and accept defeat.
"There is always speculation and rumour at this time of the season, but the key thing is that you learn your lessons. We know we are relegated but our ambition to come back is greater than ever."
Bath head coach Mike Ford: "Our timing was out as we haven't played for three weeks. However, the conditions were terrible and we've got five points with no injuries, so I'm satisfied as it's now in our hands as far as the league table is concerned.
"We now have Leinster on our mind and next week will be a totally different spectacle as we are going out there to play.
"We will have our five internationals returning but they'll be favourites as they have 50,000 behind them and have their 12 internationals back. We are looking forward to it as we've come from nowhere in Europe to be in this position."
London Welsh: Jewell, Stegmann, Reynolds, May, Awcock, Roberts, R. Lewis, Trevett, Britton, Cooper, Schofield, Down, McCaffrey, Kirwan, Fonua.
Replacements: Robinson for Roberts (66), Gilding for Trevett (66), Morris for Britton (53), Aholelei for Cooper (66), West for Down (58), Thorpe for McCaffrey (33).
Not Used: Rowley, J. Lewis.
Sin Bin: Trevett (34), Schofield (80).
Bath: T. Homer, Rokoduguni, Burgess, Eastmond, Woodburn, Devoto, Young, Auterac, Webber, Palma-Newport, Hooper, Day, Fearns, Faosiliva, Houston.
Replacements: Banahan for Rokoduguni (47), Agulla for Eastmond (63), Sisi for Young (66), Obano for Auterac (68), Batty for Webber (61), Garvey for Day (46).
Not Used: Lahiff, Cook.