The 22-year-old netminder made 28 saves on Sunday to improve to 3-0-0, stoning Alex Burrows on an overtime breakaway and stopping both Vancouver shootout attempts to lead St. Louis over the Canucks 4-3.
"I don't think many people would really think you're going to win three straight to start your career," said Allen. "But luckily for me I have. The guys have all been really helpful and I just have to focus on tomorrow now."
Burrows' OT attempt came with 30 seconds remaining but Allen shot out his glove to foil the backhand.
"I didn't really know it was his patented move but luckily I got over there and made the save," said Allen. "He had a lot of speed built up and he had a D man on his tail. I really didn't think he was going to shoot it. I just tried to wait and see which side he was going to go to."
T.J. Oshie and Andy McDonald each scored once in regulation and once in the shootout as the Blues went 3-0 on their road swing. Patrik Berglund had the other regulation goal for St. Louis (9-5-1).
Oshie's shootout goal froze Roberto Luongo, who stood motionless as Oshie skated in slowly and then whipped a shot between the goalie's legs.
"The first one kind of looked silly," said Luongo. "Sometimes you are caught trying to play the patience game. Good play (by Oshie) but at same time you want to make that save.”
Kesler and Henrik Sedin, both with their first goals of the season, and Mason Raymond scored in regulation for Vancouver (8-3-3), which has lost two straight after winning six in a row.
The Canucks looked destined to lose in regulation after the Blues took a 3-2 lead early in the third period, but Raymond tied the game on a power play with 1:47 remaining.
Canucks coach Alain Vigneault has been impressed with Raymond this season after the speedy forward struggled last year.
"He's going to the tough areas where you need to go to score goals," said Vigneault. "He's competing one on one, and he creates room for himself and his teammates. That was an important goal for us tonight because we had a real solid third period and we were behind."
The Canucks dominated the third frame, outshooting the Blues 15-3.
But it was Berglund, with his team-leading eighth goal of the season, who gave the Blues a 3-2 lead at the eight minute mark of the third.
St. Louis centre Vladimir Sobotka wheeled around Vancouver's goal and into the slot and whipped a shortside wrist shot that Berglund deflected in.
The Canucks had a golden opportunity to tie the game with a 41-second two-man advantage after Roman Polak and Alex Pietrangelo were penalized for questionable hits on Kesler. Polak had a head shot on Kesler, while Pietrangelo's came from behind.
The Blues held off that power-play attempt, but couldn't stave off Raymond on the next one.
"The last 10 minutes of the first and all of the second we played great, and then they got the momentum off those power plays, we started to get a little worn down killing penalties," said Blues coach Ken Hitchcock. "But it was a heck of a road trip."
With Allen in the fold and Jaroslav Halak returning to the ice — he backed up Allen after missing the past two weeks with a groin injury — St. Louis's goaltending situation is looking brighter after Brian Elliott struggled between the pipes, prompting Allen's emergence.
Elliott, who led the league in save percentage last season, was a healthy scratch on Sunday.
"(Allen) has really helped stabilize us," said Hitchcock. "He's just a solid guy, there's no holes in his game. It's a big step for us."
Luongo made the start for Vancouver after Cory Schneider had an off night against Dallas on Friday, allowing four goals. Luongo, who has not lost in regulation this season, made 20 saves.
He wasn't happy with the first two goals he allowed, although both were rebounds.
The teams were tied 2-2 after two periods, but it was the Blues who held a wide edge in play.
The Blues hemmed the Canucks in their own end for large stretches and dominated battles along the boards. Vancouver mustered just 11 shots through two periods.
"The second period, everybody has to realize that there's an opposition on the ice and they just took their game to a level that we had a real tough time finding," Vigneault said. "But we responded well in the third and had opportunities to win the game."
The Blues were rewarded for their tenacity early in the middle frame, when McDonald notched his third of the season after Vladimir Tarasenko hit the post.
The Canucks led 2-1 after a slow-paced first period.
Kesler opened the scoring on a Canucks power play with his first of the season. He has a goal and an assist in two games after missing 10 months with shoulder and wrist injuries. When his name was announced for the goal, Kesler drew an extended applause from the crowd.
Oshie and Henrik Sedin also tallied in the first period.
NOTES: Blues defenceman Barret Jackman tied Al MacInnis for seventh on the franchise's all-time games played list with 613. ... Defenceman Alex Edler played his 400th NHL game, all with the Canucks. ... Alexander Steen had his four-game goal-scoring streak and five-game points streak (4-5-9) snapped.