Until Colorado prevailed 5-2 on Thursday, the Sharks goalie hadn't lost a home match in regulation since 2004.
With Toskala in the net, the Sharks had a 19-game streak of earning at least a point in the Tank (16-0-3).
But Toskala's teammates didn't do him any favors against the Avalanche. Miscues and poor decisions left Toskala to cope with numerous dilemmas.
"We've been on the road so much," Toskala said of the Sharks' league-high 17 away games. "We came home, and we know we're going to stay here a while. Maybe we took our foot off the gas and thought it was going to be easy because we're going to be home now. You just have to work hard every night."
The inability to score during a two-man advantage early in the third period essentially sealed the Sharks' fate.
"I don't know what happened," Joe Thornton said. "Just bobbling pucks. The puck would never settle down for us. If we score there, it could be a different game."
Instead of cutting into Colorado's 4-2 lead, the Sharks let the moment slip away, and Joe Sakic scored his second goal a few minutes later to wrap it up for Colorado.
Toskala, who entered the game second in the league in goals-against average (1.98) and third in save percentage (.929), finished with 20 saves.
This was just the second time the Sharks have lost consecutive games this season. The previous occasion was Oct.25-26 at Detroit and Nashville, which happens to be the Sharks' next opponent Saturday.
The Sharks spent the night playing from behind thanks to some costly goofs.
"I've seen this before where it's the first game back after a fairly successful road trip," coach Ron Wilson said of the Sharks' just-completed 3-1 swing. "Sometimes you're not mentally ready to play, and that's the bottom line."
Colorado defenseman Brett Clark, who entered the game with only one goal, connected twice, including the opening goal at 11:10 of the first period.
The Avalanche had a four-on-two rush as forwards Thornton, Jonathan Cheechoo and Milan Michalek fell asleep on the play. Clark, the trailer, uncorked from the high slot.
Thornton, Cheechoo and Michalek atoned for the lapse by combining for a power-play strike at 13:39 to make it 1-1. Thornton approached the net from the bottom of the right circle, drawing defenders, then dished off on his backhand to Cheechoo for an open shot.
This ended Thornton's four-game points drought, his longest as a Shark.
FELONY CHARGES FOR BELL: Prosecutors charged Sharks forward Mark Bell with felony hit-and-run and driving under the influence Thursday, three months after an accident during the Labor Day weekend.
Bell's blood-alcohol level was "0.15 or more" when his car rear-ended a pickup truck waiting at a stop sign, according to a statement from the Santa Clara County district attorney's office. Bell, who will be arraigned Jan. 3, faces a maximum of three years and eight months in prison.
NOTES: Defenseman Kyle McLaren missed his first game of the season with what the club is calling a lower-body injury. He could return Saturday against Nashville. ... For just the second time since the inception of the award, the Sharks had co-players of the month. Goalies Vesa Toskala and Evgeni Nabokov shared honors for November.
The Associated Press contributed to this report.