Having narrowly lost the opener 2-1 after two periods of overtime, Lulea hit back strongly in game two, winning 5-2 in Gavle and take the momentum into their first two home games of the series at Coop Norrbotten Arena.
But that momentum looked to have been grounded in the eighth minute, when Axel Andersson collected the puck on the left side and found a route through to the top corner of the net, giving Brynas the lead.
That was as good as it got for the visitors, who were pegged back just over two minutes later. Facing a barrage of shots, Brynas failed to clear the puck, which finally nestled in the net after Allard's effort squeezed past Erik Kallgren.
The second period firmly belonged to Lulea, who took the lead five minutes in when Anton Levtchi sent Linus Omark through on goal, and the 38-year-old used his experience to sit Kallgren down and tap the puck home.
From then on, it was the Allard show - approaching the midway point in the match, Brynas could not cope with Lulea players flooding forward on the powerplay, and Allard had enough time in the centre of the attacking zone to pick his spot past the goaltender.
With just over two minutes to go in the second, Allard completed his hattrick and made it 4-1, again on a powerplay. Erik Gustafsson drew the defence to give the Canadian time to shoot across Kallgren and into the top right corner.
The final flourish to a brilliant display from the home side came early in the third period when a flowing team move was finished by Pontus Andreasson sweeping the puck home for 5-1.
The Norrbotten side will have the chance to move within one win of the trophy when the series stays in Lulea on Saturday, before moving back down to Gavle for game five on Monday.