DENVER — Paul Stastny didn't get the welcome home he hoped for but he got the win.
Kevin Shattenkirk had a goal and an assist and defenseman Alex Pietrangelo also scored for the Blues, who have won four straight and gave Stastny a win in his return to Denver.
"It was good to get that first game (back in Colorado) out of the way," Stastny said.
Stastny was back for the first time since signing a four-year deal with St. Louis in the offseason. He spent his first eight seasons in Colorado and left ranked eighth in franchise history with 458 points.
Despite suffering through lean years with the Avalanche, Stastny didn't receive a warm welcome from the fans. He was booed when he stepped on the ice for his first shift and the first few times he touched the puck. He didn't register a point.
"I heard 'Blues,'" Stastny said with a laugh. "You know how it is. I think if you know me you wouldn't do it. I think it's just an emotional Saturday night, so it wasn't surprising. A part of you always expects the worst. It was just different. I think after that first period I kind of settled in."
Blues goalie Jake Allen finished with 23 saves.
St. Louis dominated for most of the game but couldn't get the winner until overtime. Goalie Calvin Pickard stopped Alexander Steen on several chances in the second and third periods.
"When we were up 2-1 we really had opportunities to salt it away and it kind of came back to haunt us," Blues coach Ken Hitchcock said. "We had five or six great chances to really build a big lead."
They got the winner when Barret Jackman fed Oshie in the slot, and the big center beat Pickard with a shot over the goalie's glove.
"It's something I've worked on in practice. Just catching it and try to catch that far side," Oshie said. "It didn't get there quick but it ended up getting there eventually for the game-winner. It was a great pass by Jacks. He looked across and waited until I jumped in the hole and it was perfect timing."
Erik Johnson had both Colorado goals and Gabriel Landeskog had two assists for the slumping Avalanche, who have lost five of six. Pickard finished with 39 saves.
"It was fun," Johnson said. "Any time you can contribute it's even more fun. I'd trade those two goals to get a win tonight."
It was Johnson's first career two-goal game, and it came against his former team. His first one, on a power play, came on a slap shot from the point and gave Colorado a 1-0 lead with 5:59 left in the opening period.
His second one, with 1:24 left in the second period, tied the game at 2-all.
"I got a nice pass from (Nate Guenin) on the 3-on-2 rush and picked my spot on the blocker side," Johnson said.
In between, the Blues scored twice. Shattenkirk, who was part of the trade that sent Johnson to Colorado, tied it with a power-play goal just 1:22 after Colorado scored.
Pietrangelo gave the Blues a 2-1 lead at 8:16 of the second period with a high shot from the point.
NOTES: The Avalanche reassigned C Paul Carey and D Karl Stollery to Lake Erie of the AHL. ... Shattenkirk leads the NHL with 16 power-play points. ... Colorado center Marc-Andre Cliche returned to the lineup after missing five games with an oblique injury.