Riley Kieser and Dystin Mayo had a goal and an assist apiece for Edmonton, who won Game 1 on Saturday, 5-4.
Dakota Conroy was the lone scorer for Prince Albert, finding the back of the net 20 seconds into the third period to give the Raiders a 1-0 lead.
Prince Albert's Cole Cheveldave made 29 saves in the losing effort.
ROYALS 4 CHIEFS 3 (OT)
VICTORIA — Logan Nelson scored 2:18 into overtime as the Royals took a 2-0 lead over the Chiefs in their first-round best-of-seven set.
Tyler Soy, Brandon Magee and Logan Fisher scored in regulation for Victoria, which led 3-1 before Spokane sparked a comeback to force the extra period.
Dominic Zwerger opened the scoring for Spokane just 47 seconds into the game, and Liam Stewart and Reid Gow scored in the second and third periods, respectively, to tie the game.
Victoria's Patrik Polivka made 28 saves for the win, while Eric Williams stopped 41 of 45 shots in defeat for the Chiefs. The Royals took Game 1 on Saturday, 2-1.
THUNDERBIRDS 3 SILVERTIPS 1
EVERETT, Wash. — Roberts Lipsbergs had a goal and an assist and the Thunderbirds used a two-goal third period to seal a 2-0 first round series lead over the Silvertips.
Branden Troock and Russell Maxwell scored in the final period for Seattle, who took Game 1 of the series on Saturday, 2-1.
Carson Stadnick scored at 3:51 of the first period to put Everett on the board 1-0 before Seattle's comeback.
Thunderbirds goalie Taran Kozun stopped 26 shots for the victory. Austin Lotz made 13 saves for the Silvertips.
ROCKETS 3 AMERICANS 1
KELOWNA, B.C. — Ryan Olsen scored the eventual winner at 17:18 of the first period to give the Rockets a two-game edge in their first-round series against Tri-City.
Myles Bell scored on the power play, and Joe Gatenby also scored for Kelowna, who took the first game of the series 3-1 on Saturday.
Philip Tot opened the scoring with a goal at 10:37 of the first period for the Americans, who were outshot 47-25.
Jordon Cooke stopped 24 shots for the Rockets, and Tri-City's Eric Comrie made 44 saves.
WHEAT KINGS 8 PATS 4
REGINA — Tim McGauley scored two goals and helped on another and Brandon used a five-goal second period to power past Regina and take a 2-0 lead in their best-of-seven first-round playoff series.
Richard Nejezchleb had a goal and two assists, Ryan Pulock and Ryley Lindgren had a goal and an assist apiece, and John Quenneville, Nolan Patrick and Jens Meilleur also scored for the Wheat Kings, who took the first game of the set on Saturday, 6-3.
Boston Leier and Connor Gay had a goal and an assist apiece for the Pats, who were outshot 44-31, and Dryden Hunt also scored. Morgan Klimchuck chipped in with a short-handed goal in the second period.
Wheat Kings goaltender Jordan Papirny made 27 saves for the victory.