After impressing with back-to-back wins over the Dragons and Knights, the Warriors attack lacked direction and energy while their defence through the middle was caught short as the home side controlled the speed of the ruck through strong running and quick play-the-balls.
The result means the Warriors face a battle to win a home final while they remain vulnerable in eighth spot on the premiership ladder on 28 competition points, four points ahead of the ninth-ranked Wests Tigers.
With only two rounds remaining in the regular season the Warriors will continue to tread a tightrope towards the playoffs and need to win at least one of next Friday's crucial home game against Penrith and their final round encounter against Canberra at Mt Smart Stadium.
"That wasn't us," said coach Stephen Kearney. "Their tries were too easy. "We fought our way back into the contest right at the back end there and credit to them, [the Bulldogs] have had a really positive month of footy.
"We knew it was going to be hard work for us but we were a little bit off in certain areas, which is pretty disappointing given what was potentially at stake."
There are concerns however for the health of five-eighth Blake Green who departed with a calf injury with 11 minutes to go, while centre Gerard Beale pulled a hamstring and halfback Shaun Johnson also suffered an ankle problem in the second half but saw out the rest of the match.
Beale and captain Roger Tuivasa-Sheck scored first half tries for the visitors but three four-pointers to Adam Elliot, Reimis Smith and Lewis were complemented by four goals to Rhyse Martin to give the Bulldogs an eight point advantage at the break.
Match officials missed a forward pass from Canterbury captain Josh Jackson to centre Kerrod Holland in the lead-up to Lewis' try, but the Warriors had only themselves to blame for letting the result slip away.
Both sides traded tries early in the second half with right wing David Fusitu'a scoring for the Warriors and centre Josh Morris replying for Canterbury, before Fusitu'a dived in for his second to leave the visitors trailing 26-20 near the end of the third quarter.
Forward Adam Blair produced an offload for replacement back Peta Hiku to dive over near the posts and halfback Shaun Johnson's fourth conversion brought them level with four minutes remaining, before Lewis's one-pointer broke the deadlock at the death.
"The boys fought back and I thought we were starting to pick up in the second half but just too late," said Tuivasa-Sheck.
Bulldogs 27 (Adam Elliot, Reimis Smith, Lachlan Lewis, Josh Morris tries, Rhyse Martin 4/4 cons, 1 pen, Lewis field goal)
Warriors 26 (Gerard Beale, Roger Tuivasa-Sheck, David Fusitu'a 2, Peta Hiku tries, Shaun Johnson 3/5 cons)
