Niemi made 41 saves, including the key pad stop on Carter in overtime.
Jake Muzzin and Dustin Brown scored for Los Angeles, who fell into a tie with San Jose in the battle for home-ice advantage in the first round of the playoffs. Jonathan Quick made 33 saves as the Kings lost their fourth straight road game.
BLUES 2, CANUCKS 1, SO
In St Louis, Missouri, Jay Bouwmeester tied it midway through the third period, and Andy McDonald and Alex Steen scored in the shootout to lead St Louis over Vancouver.
Brian Elliott made 21 saves through overtime and stopped Derek Roy and Alexandre Burrows in the shootout, solidifying the Blues’ chances in a tight Western Conference race. Bowmeester’s goal was his first since joining the Blues in a trade-deadline deal.
Alexander Edler scored on a power play late in the second period for Vancouver. Cory Schneider made 35 saves, but surrendered two goals on three shootout chances.
The Canucks played for the third time in four nights, all on the road, and had trouble generating much offense coming off a 5-2 victory at Nashville on Monday.
Blues coach Ken Hitchcock earned his 600th career NHL win against the franchise he beat for his first victory, when Dallas won in Vancouver on Jan. 22, 1996.
SENATORS 3, HURRICANES 2
In Ottawa, Craig Anderson made 32 saves to help Ottawa beat Carolina for their third straight win.
Mika Zibanejad, Cory Conacher and Chris Neil all scored as Ottawa remained in sixth place in the Eastern Conference, one point ahead of the New York Islanders.
Justin Faulk and Eric Staal scored for the Hurricanes, who got 31 saves from Justin Peters.
The Senators returned to Ottawa from Boston amid tightened security measures a day after the bombings at the Boston Marathon. Their game against the Bruins, postponed on Monday, was rescheduled for April 28.
Ottawa defenseman Jared Cowen played his first game since undergoing hip surgery in November last year that was expected to end his season.
WILD 5, OILERS 3
In Edmonton, Alberta, Kyle Brodziak scored a pair of goals, and Minnesota earned another late-season win by topping Edmonton.
Charlie Coyle, Mikael Granlund and Zach Parise also scored for the Wild (24-16-3), who are 2-0-1 in their past three games after losing five of six. Minnesota remained in sixth place in the Western Conference playoff race.
Nail Yakupov, Magnus Paajarvi and Shawn Horcoff had goals for the Oilers (16-19-7), whose slim playoff hopes took another hit. Edmonton have lost six in a row on the heels of a five-game winning streak.