Anze Kopitar and Lubomir Visnovsky scored on power plays for the Kings, who also got goals from Brian Willsie and Alexander Frolov.
The Kings were penalized with 2:06 left in regulation for having too many men on the ice. But Blake got the equalizer, converting his own rebound just two seconds after the bench minor expired. The goal, which came after Los Angeles goalie Sean Burke was pulled for an extra attacker, ended a 16-game drought for Blake.
John-Michael Liles, Brett Clark and Milan Hejduk scored power-play goals for the Avalanche, and Andrew Brunette had three assists in a matchup of last-place teams. Ian Laperriere also scored and Marek Svatos extended his goal streak to three games.
Frolov's 32nd goal narrowed Colorado's lead to 4-3 with 10:57 left in the third period, but Hejduk responded with his 23rd goal less than four minutes later while Tom Kostopoulos was off for hooking.
Visnovsky's 17th of the season made it a one-goal game again with 4:46 left, following a hooking penalty against Paul Stastny.
Liles gave Colorado a 3-2 lead 61 seconds into the third period, beating Burke with a screened 15-foot wrist shot while Kings defenceman Brent Sopel was serving a delay-of-game penalty. Burke then left a bad rebound on a shot from the left circle by Ben Guite, and Svatos banged it home with 15:22 remaining for his 14th goal.
Down 2-0, Colorado got on the board at 4:42 of the second during a 5-on-3 advantage after Mattias Norstrom got a delay-of-game penalty and Aaron Miller went off for hooking 58 seconds later.
Joe Sakic carried the puck out from behind the net away from Sopel and then slipped it to Clark, whose 25-foot snap shot from the slot beat Burke to the glove side with 15 seconds left on Norstrom's penalty.
Laperriere tied it at 11:23 of the second with his fifth goal. He caught up with a loose puck that caromed off teammate Mark Rycroft in the Avalanche zone, went in alone on Burke and beat him with a short backhander.
Laperriere, who also got into a fight with Kostopoulos in the first period, has an NHL-leading 15 fighting majors this season. He had 61 goals and 1,017 penalty minutes in his nine seasons with the Kings, and now has four goals in 12 games against his former team.
Sakic, the newest member of the 600-goal club, extended his assist streak to 10 games and tied Tampa Bay's Martin St. Louis for the longest such streak this season. The Colorado captain has 14 assists and five goals during that stretch, increasing his career point total to 1,563 - the most among active players. His next game will be his 1,300th in the NHL.
Notes: Willsie was a sixth-round pick by the Avalanche in the 1996 draft and signed with the Kings as an unrestricted free agent on July 4. He scored seven goals in 69 games with Colorado and had a career-high 19 last season for Washington. ... Colorado LW Wojtek Wolski turned 21, but missed his fourth straight game because of a concussion. ... Colorado was 3-for-6 on the power play. It was only the second time in 24 games that the Avalanche had more than five power-play opportunities. ... Willsie's goal was his first in 20 home games since Nov. 16 against Philadelphia.