Boston notched a vital 3-2 overtime victory at Detroit to move within one win of a place in the next round of the NHL playoffs, while Los Angeles avoided elimination and Minnesota squared their series against Colorado.
Boston's Jarome Iginla scored with 6:28 minutes left in overtime on a shot that went off an opponent, completing a comeback from a two-goal deficit and giving the Bruins a 3-1 series lead.
Detroit took a 2-0 lead early in the second period after Pavel Datsyuk and Niklas Kronwall each had a goal and an assist.
Torey Krug pulled a goal back for the Bruins midway through the second period and Milan Lucic tied it 2-2 early in the third period.
Detroit's Jonas Gustavsson made 37 saves in a surprise start, filling in for Jimmy Howard, who was ill.
The Presidents' Trophy winners and defending Eastern Conference champions can advance with a win against the Red Wings at home.
Kings beat Sharks
Los Angeles had to win at home to avoid a series sweep against San Jose and did just that, winning 6-3 to cut the series deficit to 3-1.
Justin Williams and Marian Gaborik scored two goals each while captain Dustin Brown had a goal and an assist, and Tyler Toffoli scored on his 22nd birthday during a three-goal second period.
James Sheppard, Matt Nieto and Joe Pavelski scored for the Sharks.
Minnesota's Charlie Coyle scored his third goal of the series and helped the Wild defeat Colorado 2-1 to lock up the series 2-2.
The Wild outshot the Avalanche a stunning 32-12, establishing a franchise record for fewest allowed by Minnesota. Colorado has been outshot 78-34 in the past two games, with Ryan O'Reilly getting the only goal.
Jared Spurgeon used a slap shot to get a puck past Colorado's Semyon Varlamov just 3:47 minutes into the game to give the Wild the early advantage.