Gabriel Landeskog scored the game's only goal 5:26 into the second period as Colorado improved to 8-1, the best start in franchise history.
The game was billed as a fight for bragging rights between Pittsburgh star Sidney Crosby and Colorado rookie Nathan MacKinnon. The former No. 1 picks both are from Cole Harbour, Nova Scotia in Canada.
Instead, Giguere stole the show. Pittsburgh went 0 for 7 on the power play and lost for the first time at home despite outshooting the Avalanche 34-14.
Marc-Andre Fleury stopped 13 shots for the Penguins (7-2).
SHARKS 1, RED WINGS 0, SO
DETROIT (AP) — Logan Couture scored in the shootout and San Jose beat Detroit.
The Sharks (8-0-1) are the NHL's last team without a regulation loss.
Each goalie got a shutout for not allowing a goal in 65 minutes.
It was Niemi's third shutout against Detroit. He also stopped Todd Bertuzzi on Detroit's final shootout attempt with a spectacular pad save.
It was the first game of a four-game Eastern road swing for San Jose.
FLAMES 3, KINGS 2
LOS ANGELES (AP) — T.J. Brodie scored the tiebreaking power-play goal with 29.7 seconds to play, and the Flames rallied for a victory over the Kings.
Brodie collected a bouncing puck in the slot and beat Jonathan Quick for the third power-play goal of the night for the Flames, who had lost on the first two stops of their five-game trip.