Smyth deflected Jason Smith's shot from the right point past Jose Theodore for his second goal, breaking a 2-2 tie just 20 seconds into the third period. Less than four minutes later, Sykora's wrist shot from the slot dribbled between Theodore's pads.
Colorado pulled to 4-3 when Milan Hejduk poked a pass from Paul Stastny past Dwayne Roloson on a break at 11:50. The Avs pulled Theodore with 1:15 left, but Roloson, who saved 39 shots, didn't buckle on the way to his 100th career win.
The Avs hadn't played in six days, a layoff longer than the all-star break in January, and their rust showed.
Colorado was the last NHL team to allow a power-play goal. After killing 15 penalties, including three Saturday night, the Avs finally succumbed when Smyth tied it 2-2 at 17:14 of the second period.
Colorado defenceman Ken Klee left Smyth unattended on the opposite side of the crease, and Shawn Horcoff found him with a pass while Avs defenceman Karlis Skrastins was in the penalty box after flipping the puck into the seats.
Smyth has scored five goals and six points in two games. His fifth career hat trick Thursday night led Edmonton past San Jose 6-4.
The Avs took a 2-1 lead earlier in the second period when Tyler Arnason took the puck off the short boards and wove his way to the left circle, where he flipped a wrist shot over Dwayne Roloson's right shoulder.
Avs rookie Wojtek Wolski scored his third goal of the season when he sent the puck past Roloson from the slot after Klee's shot from the right point at 8:07 of the first period.
Thirty-nine seconds later, the Oilers tied it 1-1 when Sykora deflected Daniel Tjarnqvist's slap shot past Theodore.
Notes: The game was delayed for more than 10 minutes in the third period when the glass broke near the Avalanche goal. ... Avs D Jordan Leopold, who had a hernia operation in August, wasn't able to finish practice Friday, putting his plan to return to action next week in question. ... Edmonton didn't manage a shot on goal during its first power play and only two each on its next two.