The Avalanche are 4-0 under new coach Patrick Roy, their best mark since the franchise relocated from Quebec to Colorado for the 1995-96 season.
Giguere, making his first start of the season, made several sparkling saves. His best came midway through the second period when he stoned Patrice Bergeron on a 2-on-1 rush.
Ryan O'Reilly gave the Avalanche the lead in the final minute of the first period and Matt Duchene sealed the win with an empty-net goal in the closing seconds.
Andre Benoit and Duchene assisted on O'Reilly's goal.
Tuukka Rask stopped 28 shots for Boston and has allowed only three goals in three games. Boston was blanked for the first time in 72 games.
DUCKS 6, RANGERS 0
ANAHEIM, Calif. (AP) — Jakob Silfverberg scored twice, Jonas Hiller made 34 saves for his 17th NHL shutout, and Anaheim routed the New York Rangers in the home opener of the Ducks' 20th season.
Teemu Selanne and Mathieu Perreault assisted on both goals by linemate Silfverberg, who had the second two-goal game of his career. He has scored four goals in his first four games with the team. Dustin Penner and Daniel Winnik each added a goal and an assist.
New York has been outscored 20-6 to start their first season under new coach Alain Vigneault. The Rangers lost 9-2 at San Jose on Tuesday.
The Ducks outshot the Rangers 37-34 for their third win in a row in the teams' first meeting in nearly two years.
Playing without injured All-Star forward Rick Nash, the Rangers fell to 1-3 on their nine-game trip, the longest to open a season in franchise history.
New York's Henrik Lundqvist, a finalist for the Vezina Trophy last season, stopped 31 shots in losing for the third time in four games.
HURRICANES 3, CAPITALS 2
WASHINGTON (AP) — Nathan Gerbe scored the tiebreaking goal at 6:59 of the third period, Anton Khudobin stopped 30 shots, and Carolina beat Washington.
Elias Lindholm and former Capitals forward Alexander Semin also scored for the Hurricanes.
Jason Chimera and Alex Ovechkin had goals for the Capitals, who won four of five from Carolina last season. Ovechkin has seven points (five goals, two assists), the most he has had after four games since 2010.
The Capitals went 0 for 5 with the extra man after converting six of 12 power-play opportunities during their first three games.
BLUE JACKETS 4, SABRES 1
BUFFALO, N.Y. (AP) — Marian Gaborik had a goal and two assists, and Columbus kept Buffalo winless.
Cam Atkinson, Nick Foligno and Brandon Dubinsky also scored for Columbus. Sergei Bobrovsky made 26 saves for the Blue Jackets.
Thomas Vanek scored for Buffalo, and Ryan Miller stopped 29 shots for the Sabres, who fell to 0-4-1. It is their worst start since they went 0-5-2 to open the 1999-2000 season.
COYOTES 4, RED WINGS 2
DETROIT (AP) — Michael Stone's goal with 4:47 left broke a tie and lifted Phoenix over Detroit.
Derek Morris and Antoine Vermette both had a goal and an assist, and Mikkel Boedker also scored for Phoenix. Mike Smith made 28 saves.
Joakim Andersson and Jonathan Ericsson scored for Detroit, and Jimmy Howard stopped 35 shots. Andersson and Ericsson scored 53 seconds apart early in the second period to give the Red Wings a 2-1 lead.
Stone fired a slap shot from the right point that went through teammate Martin Hanzal's and caromed in off the far goal post. It came 2 seconds after a Coyotes' power play ended.
Vermette added an empty-net goal in the last minute.
LIGHTNING 7, PANTHERS 2
TAMPA, Fla. (AP) — Steven Stamkos had three goals and an assist, Valtteri Filppula added two goals, and Tampa Bay routed Florida.
Martin St. Louis added a goal and an assist for the Lightning, who have won three in a row after a season-opening loss at Boston. Ben Bishop improved to 3-0.
Florida, which lost three of four during a season-opening road trip, got goals from Brad Boyes and Jonathan Huberdeau.
Stamkos, second in the NHL with 29 goals during the abbreviated 2012-13 season, stopped a five-game scoring drought, dating to last season. The centre completed his sixth NHL hat trick with a one-timer from the top of the left circle during a power play at 12:25 of the third.
WILD 2, JETS 1
ST. PAUL, Minn. (AP) — Matt Cooke's goal gave Minnesota the lead in the second period, and Josh Harding made 14 saves for the Wild in a victory over Winnipeg.
Jonas Brodin scored first for the Wild on Ondrej Pavelec, who stopped 28 shots. He has played all four games for the Jets and allowed 12 goals. Minnesota improved to 1-1-2.
Bryan Little's goal in the final minute of the first period during a 5-on-3 power play tied the game for the Jets, who were outplayed from start to finish in their first road game of the season.
After scoring five goals in each of their first two games, the Jets have only three goals and 32 shots over their last two contests.
MAPLE LEAFS 4, PREDATORS 0
NASHVILLE, Tenn. (AP) — Jonathan Bernier made 36 saves, and Phil Kessel had a goal and two assists to lead Toronto past Nashville.
James van Riemsdyk, Tyler Bozak and Joffrey Lupul also scored for the Maple Leafs, who have won four of five this season. Nashville has lost three of four.
Bernier extended his domination of Nashville, improving his record against the Predators to 8-1. He stopped eight shots in the first period, 17 in the second and 11 in the third for his first shutout this season and the seventh of his NHL career.
After a scoreless opening period, Kessel scored the first goal at 13:41 of the second.
SHARKS 4, CANUCKS 1
VANCOUVER, British Columbia (AP) — Antti Niemi made 25 saves, and Matt Pelech scored his first NHL goal as San Jose stayed perfect by topping Vancouver.
Marc-Edouard Vlasic, Patrick Marleau and Brent Burns also scored for the Sharks (4-0).
San Jose also beat the Canucks 4-1 in both teams' season opener after sweeping Vancouver four straight in the first round of last season's playoffs. Joe Thornton and Logan Couture added two assists.
San Jose hasn't lost to the Canucks since Jan. 21, 2012. Sharks forward Tomas Hertl, who scored four goals on Tuesday against the New York Rangers, was held pointless.
Mike Santorelli scored for the Canucks (3-2), who got 25 saves from Roberto Luongo.
CANADIENS 4, OILERS 1
EDMONTON, Alberta (AP) — Brendan Gallagher and Alex Galchenyuk each had a goal and an assist, and Montreal won for the second time in three outings, defeating Edmonton.
Brandon Prust and Max Pacioretty also scored, and P.K. Subban had three assists for the Canadiens (2-2), who made their second stop on a four-game Western Canadian trip.
Ryan Smyth scored for the Oilers (1-3), who will start a six-game road trip.
Edmonton's best early opportunity came 11 minutes in when defenceman Justin Schultz pinched in from the point and had a point-blank shot on net, but hit Montreal goalie Peter Budaj in the face, ripping off his mask.