The Dragons led by a Ben Hunt double, scored three first half tries to lead 18-0, before adding a further four tries in the second half to claim their third victory of the season.
Canterbury’s only try and points came in the 75th minute when Reimis Smith crossed in the corner to grab his fourth try of the season.
The Dragons were first to score when centre Euan Aitken forced his way over in the 14th minute before a clever Ben Hunt one on one strip created a long-range break and the following play Tim Lafai scored out wide.
Winger Mikaela Ravalawa crossed on the right flank in the 34th minute and Lafai converted to send the home side into half time leading 18-0.
The Dragons were first to score in the second 40 when quick hands by Matt Dufty and Lafai put winger Jordan Pereira over out wide.
Hunt grabbed his first try of the afternoon in the 63rd minute toeing ahead a loose Kerrod Holland pass to give St George a 28-0 lead.
The halfback was involved again eight minutes later when Jayden Okunbor came up with an error to allow Hunt to pick up the loose ball and send Zac Lomax over for his first NRL try.
The Bulldogs try came four minutes later when Reimis Smith finished off a nice backline play down Canterbury’s right edge, before Corey Norman split the Dogs defence in the final minute of the match to find his halves partner Hunt, who scored under the posts. Rookie Lomax converted the try to give the home side a 40-4 victory.
It was a sorry performance from a Bulldogs side whose 24 missed tackles tripled that of the Dragons’ eight.
“It’s obviously a real learning curve. You can’t make errors and continue to make errors,” Bulldogs coach Dean Pay said.
“We need to stop that, stop the stem of making those simple errors. But we need to make sure that we’ve got some resilience to defend them as well.”