The Blues, who average 3.36 goals per game, missed a chance to pull even with Chicago atop the Central Division by losing just their fourth game against an Eastern Conference team.
"Hard to find a lot of good players in our game today," St. Louis coach Ken Hitchcock said. "They deserve a lot of credit. They skated. They checked. They played hard. And we looked like we had the body language like we wanted an easier game. Didn't get it."
"You need the post to be a goalie's best friend," Carolina coach Kirk Muller said.
Semin then tacked on his highlight-reel empty-net goal that capped the Hurricanes' best month in a while.
They went 10-4 in January, and their previous 10-win month in March 2009 led into their only playoff appearance since 2006, when they won their only Stanley Cup.
Skinner put Carolina up 2-1 off a draw 1:51 into the second. After Jordan Staal won a faceoff, the puck found Skinner's stick and he beat Halak with a wrist shot from the slot that clipped the goalie's glove for his seventh goal of the month.
"Didn't really mean to bank it off his glove and in," Skinner said. "You just try and get it to the net sometimes."
That turned out to be enough support for Khudobin, who earned the decision in every game this month for Carolina.
He helped the Hurricanes leapfrog idle Columbus and Philadelphia in the division standings, with 59 points. When the night started, only 11 points separated second place from the cellar in the Metropolitan.
The Hurricanes never trailed on Friday, taking advantage of some sloppy play early by the Blues -- who were whistled for three penalties in the opening 11:25. Carolina went up 1-0 when Gerbe one-timed a slick cross-ice pass from Andrej Sekera 3:46 in.
"The puck had moved, and there was an opening there and he found a soft area," Sekera said. "He was wide open, so I just tried to get it to him, and he did a pretty good job."
The Blues, who have the league's second-best power-play unit, tied it at 9:23 when Backes beat Khudobin high for his 150th career goal with St. Louis but just his second since Dec. 14.
"It's nice to be back on the scoreboard but we're more interested in winning," Backes said. "Tonight was a game where they brought a hard-skating, tough-checking game, and we didn't have a ton of answers for it."
St. Louis finished the month 9-5-0. ... The Blues entered with 37 points on the road, the second-best total in the league, but have not won in Raleigh since 2009. ... Carolina G Cam Ward, out all of January with an unspecified lower-body injury, made a conditioning start Friday night with Charlotte of the AHL.
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RALEIGH, NC - JANUARY 31: T.J. Oshie #74 of the St. Louis Blues leaves the ice following warm-ups prior to an NHL...