VANCOUVER—Jonathan Toews and the Blackhawks have kept their cool while the Vancouver Canucks have lost theirs.Now they are just one win away from a return trip to the Western Conference finals.Toews scored three power-play goals and added two assists as the Blackhawks beat Vancouver 7-4 on Friday and grabbed a 3-1 lead in the second-round series. The more the Canucks have taken bad penalties and displayed a lack of discipline, the more the Hawks made them pay with a lethal power play.Patrick Sharp also scored on the power play and Tomas Kopecky added a goal shortly after another expired. the Hawks, who went 4 for 8 with the man advantage, has won three straight after dropping the series opener at home.Brent Seabrook scored 18 seconds in, Dave Bolland scored into an empty net with 37 seconds left, and Antti Niemi made 26 saves for the Hawks, who can advance to hockey’s final four with a win at home on Sunday.After talking a lot between games about the need for better discipline and get more bodies to the Hawks net, Vancouver instead spent most of the night marching to the penalty box.

“We lost our composure again,” said Roberto Luongo, who made 27 saves,but continues to play awful in the Vancouver Nets. “I don’t know why it happened. We were all on the same page before the game, and I don’t know.” The Hawks are again inside Luongo’s head.

Dustin Byfuglien, who scored three goals in Game 3, was a big part of it.He combined with Toews to set up Seabrook’s goal on the first shift, and then drew consecutive cross-checking penalties on defenseman Shane O’Brien. The 6-foot-4, 257-pound Byfuglien went straight to the net on the second, screening Luongo while Toews ripped a shot past both of them. It was clear what side of that line the Canucks were on in the second period.Toews, who had three assists in Game 3, added his second power-play goal 33 seconds into the middle period to put the Blackhawks ahead 3-2. Sharp doubled that lead on a power play rebound scramble at 12:47, and the Canucks came apart.Daniel Sedin was penalized for breaking his stick across Kris Versteeg after a whistle, and Alex Burrows cross-checked Byfuglien in the neck during a scramble. Toews converted the 5-on-3 advantage with 4:38 left in the period.Daniel and Henrik Sedin, Kyle Wellwood and Alexander Edler scored for the Canucks, who lost consecutive home games for the second time this season.Luongo has given up 13 goals the last seven periods.

“He’s the second-best goaltender on the ice,” Coach Alain Vigneault said.

NOTES—The Hawks are 7 for 24 on the power play in the series, and converting at 34.6 percent in the playoffs. The Canucks’ penalty-killing is last in the playoffs at 64.3 percent….Demitra led the Olympics with 10 points in seven games. He had six points in nine playoff games, but the Slovakian forward had only one assist against the Blackhawks.