First-five Chris Noakes was the star turn with a personal haul of 25 points - two conversions, six penalties and a drop goal - as the Steamers piled into the first half, careering to a 29-3 lead and cutting the gun-shy and error-prone Cantabs to pieces with aggression, Noakes' unrelenting positional kicks and an eye for the half-chance.
Canterbury were clueless at how to curb the onslaught, falling off 12 tackles as Bay rolled in tries through fullback Toby Arnold and skipper Colin Bourke.
Arnold's five-pointer was one of the best this season, launched by Phil Burleigh 80m out, with Sam Cane and Jamie Nutbrown featuring. Bourke started and finished his try, aided by a pearl of a pass from Tanerau Latimer.
Bay didn't match their first-half intensity after the break as Canterbury powered back, slicing the deficit to 24-32 midway through the spell after tries to lock Luke Romano, halfback Willie Heinz and second-five Ryan Crotty.
Centre Robbie Fruean set up their bonus point fourth try when he split the defence to send replacement wing Telusa Veainu over four minutes from fulltime. Perrin, who'd been subbed by then, watched the last few minutes through his fingers as Bay clung to a one-point lead.
" I had my eyes closed for most of it. We were pretty lucky in the end to hold them out - obviously they'd gotten a rark up and brought a physical edge to things that wasn't there in the first half."
Perrin said a return to the formula that had served the side so well early in the campaign was the catalyst for the lift in intensity.
"We backed ourselves and believed in ourselves and went back to... running hard, us forwards being aggressive at the breakdown and set piece, although that still needs some work."
Canterbury coach Rob Penney was less-than-enamoured with referee Chris Pollock's work, quizzing the whistler outside the changing sheds on two key decisions - awarding Arnold's try when the linesman has raised the possibility of a forward pass, and the penalty dished out when opposing wings Johnny McNicholl and Ben Smith clashed, sparking a first-half brawl.
Penney's beef with the Arnold try was that the touch judge had indicated a forward pass but a problem with the sound meant Pollock didn't get the message.
"Polly initially didn't award the try, and then gave it based on his own conclusion.
"Obviously outcomes won't be changed but it was at a critical stage and allowed Bay to get off to a bit of a flyer."
