Mikael Samuelsson scored the go-ahead goal in the third period, Roberto Luongo made 30 saves and the Vancouver Canucksmoved within a victory of sweeping the defending Stanley Cup champion Blackhawks after a 3-2 win on Sunday night. The Canucks, with the best record in the NHL during the regular season, lead the first-round series 3-0 and can finish it off Tuesday night at the United Center.Christian Ehrhoff and Daniel Sedin also scored for the Canucks, eliminated by the Blackhawks in the first round the previous two seasons.Duncan Keith and Patrick Sharp had power-play goals for the Blackhawks, but it was a night of missed chances. The Blackhawks had seven power-play opportunities overall, including a 5-on-3 in the first period when they led 1-0, but were turned away by Luongo and the Canucks’ penalty kill. Samuelsson, who missed Game 2 with an illness, scored on a second rebound at 6:48 of the third after a first attempt by Henrik Sudin went off goalie Corey Crawford.