But as it turned out, that was plenty of time for Colorado's Erik Johnson and ex-Shark Jamie McGinn to score -- and for San Jose's Joe Pavelski to answer with a game-tying goal with 20 seconds left, forcing overtime.
The Sharks survived that wild third period and defeated Colorado 5-4 in a shootout with Logan Couture and Patrick Marleau beating Avalanche goaltender Semyon Varlamov and San Jose's Antti Niemi stopping both shots he faced.
"It was a crazy ending," Sharks forward Brent Burns said. "I'm sure coaches don't like seeing that too often. I think we got angry a little bit, but as a group I think we're pretty confident and it was just a matter of who was going to step up and get that next goal, and [Pavelski] did."
The Sharks won their 11th straight regular-season home game against Colorado. The Avalanche's last regular-season win at San Jose was on Feb. 6, 2008.
The Sharks improved to 8-0-1 in their past nine games at SAP Center and are 13-1-3 for the season. They've won back-to-back games, both in shootouts.
Johnson and McGinn scored 12 seconds apart to give Colorado a 4-3 lead, but with Niemi on the bench for an extra attacker, Pavelski took a pass from Joe Thornton and scored from the slot. Pavelski has six goals in the past seven games.
"Pav has been a real clutch player over the past two weeks for us, he's kind of the go-to-guy right now," Sharks coach Todd McLellan said. "He seems to be getting it done. He did it again tonight for us. We're happy for him and for us."
Johnson tied the game 3-3 on a slap shot from the blue line at 18:09, four seconds after a Colorado power play expired. Colorado had pulled Varlamov late in the power play and had an extra attacker on the ice when Johnson scored.
McGinn then deflected John Mitchell's shot from the left circle past Niemi to put Colorado ahead.
"It's frustrating because we tied it late and then took the lead late," Johnson said. "Then they tied the game and somebody had to win the skills competition at the end.
"It was a strange game probably from the perspective of both teams. A very strange game at the end. It was a high to tie it, a high to go ahead and then a crashing low when they tied it. There's not a lot to look at and be happy with. I'm glad for the point but disappointed we didn't get the win."
Varlamov made 41 saves in 65 minutes. Niemi stopped 29 shots.
"It's too bad," Colorado coach Patrick Roy said, "but at the same time we showed a lot of character. We had a good start and I thought we played well in the third period. We scored two big goals and then they made a great play to tie it."
The Sharks had gone 0-for-12 on the power play in their previous four games before getting power-play goals from Demers and Irwin. McLellan shuffled his power-play units, and the changes paid off.
"I got tired of watching them not get anything done, to tell you the truth," McLellan said. "We did as a group. I haven't felt that we've had a competitive set of power plays. What I mean by that is two groups that can fight for the ice time. It was just every time a power play came, a group of players would stand up and go out. Whether they got it done or not, the next group would go out and we just got in a rut.
"Now they don't know who we're starting. Now they all want that time. If one group is more productive than the other, they'll get it It's a little bit more competitive amongst each other."
The Avalanche built a 2-1 lead in a spirited first period that featured two fights in the first meeting of the season between the teams.
MacKinnon gave Colorado a 1-0 lead at 11:05 with a power-play goal after drawing a tripping penalty on Tommy Wingels. He fired a shot from the high slot that deflected off of San Jose defenseman Andrew Desjardins' stick and past Niemi.
The Sharks pulled even at 13:59 on Demers' power-play goal. From near the goal line, Thornton angled a pass above the left circle to Demers, who ripped a shot over Varlamov's shoulder and inside the left post.
Demers had gone 44 regular-season games without a goal before scoring his first of the season Saturday night against the Dallas Stars. Now he has goals in back-to-back games.
Colorado moved ahead again with 49 seconds left in the period when Landeskog scored his 10th goal of the season on an odd-man rush. Landeskog took a pass from Paul Stastny in the slot and hammered the puck past Niemi, inside the left post.
Colorado outshot the Sharks 15-13 in the first period, but San Jose dominated the second. The Sharks outshot the Avalanche 21-5 and outscored them 2-0 in the period to build a one-goal lead.
Burns scored his 10th goal of the season at 5:53 to get the Sharks even. From along the right boards, Thornton hit Burns with a pinpoint pass above the right circle, and Burns blasted a shot inside the right post. The goal was Burns' second in four games after going eight games without a goal.
Irwin, who had hit the post with an earlier shot, scored a power-play goal at 13:02 to put the Sharks ahead for the first time. With Marleau providing a screen in front of Varlamov, Irwin scored his second goal of the season on a slap shot from the left point.
"It just reminds us we got to get back to the basics and what makes our power play successful and that's getting pucks to the middle, shooting it, moving well on the point, using each other and getting bodies and pucks to the net," Irwin said of the new-look power play units. "It's very simplified, but I think that's what makes us successful."
Earlier in the day, the Sharks announced that rookie forward Tomas Hertl would undergo surgery on his injured right knee within a week and would be out for more than a month. General manager Doug Wilson said Monday night that doctors are expected to repair two problems and check to see if there's other damage that needs to be fixed. Hertl was injured during a knee-on-knee collision with Los Angeles Kings captain Dustin Brown on Thursday night at Staples Center.
McLellan continued shuffling his lines in the wake of Hertl's injury. Thornton and right wing Burns were reunited after spending one game apart and skated with Pavelski on the top line. Couture centered a line with Marleau and Wingels.