But the 35-year-old side-stepped questions about hanging up his boots after the match and said: "I'm keeping my powder dry just a little bit longer. I'm not retiring just yet."
Dallaglio was one of eight players under the weather after an illness swept through the Wasps training camp, leaving director of rugby Ian McGeechan fearing the worst.
"We had a lot of sick players this week and eight were doubtful, so it was a hell of a performance from so many players who were short of energy," McGeechan said.
"We had a bug going round - Tom Rees and John Hart were out - and the others did a great job. This morning I was worried that we might be a bit vulnerable.
"Lawrence is playing very well at the moment and played very well today having only just got off his sick bed and not training all week."
Paul Sackey's two tries - his 60th and 61st in the Premiership - took him past Neil Back (59) into second place in the all-time rankings behind Sale's Steve Hanley (75).
Rob Webber, a hooker playing in the back row because of Rees's illness, touched down early on with Danny Cipriani adding two conversions and two penalties.
"We knew we had to start well because in the second 40 minutes we'd have to make lots of changes," added McGeechan, who still harbours hopes of a place in the end-of-season play-offs.
"We took five points against Newcastle, two last week, four today and we've just got to keep collecting them now and aiming at that fourth spot."
Bath only came to life late in the game when Joe Maddock crossed under the posts and Olly Barkley added a conversion and penalty.
"I'm disappointed, particularly with the way we played in the first 40 minutes when we were probably too conservative and missed a few one-on-one tackles," said Bath head coach Steve Meehan.
"We gave Wasps the opportunities and they took them well."
Meehan defended his decision to rest a number of key players, including fly-half Butch James and in-form wing Matt Banahan, despite going into the game level on points with Gloucester at the top of the table.
And he took issue with the yellow card issued to Danny Grewcock for stamping by referee Rob Debney, claiming the England lock's reputation makes him an easy target for officials.
"People have got carried away with where we are at the moment. We're only half-way through the season," he said.
"We've done well this season using the whole squad and Butch has played a lot of rugby so it's a question of making sure we don't blow him out.
"I've heard descriptions that the yellow card was anything from harsh to ridiculous.
"If Danny's on the field when anything happens he does tend to attract attention. From our point of view we don't think he deserved a yellow card."