Backes had a goal and assist in the first period to lead the Blues to a 4-2 win over the Nashville Predators in the season opener for both teams.
St. Louis scored three times in the first 9:45 to jump in front 3-0 and chase Nashville goalie Pekka Rinne.
The early scoring came on the heels of the Cardinals' 9-1 win over Pittsburgh in the opening game of the NL Division Series.
The start of the hockey game was moved back 30 minutes to allow the fans time to make the five-block trek from Busch Stadium,
"The Cards scored nine today, we were trying to keep up," Backes said.
The baseball game was shown on the scoreboard before the Blues game, charging up the already crazed crowd.
Watching the Cardinals roll to an easy win set the tone for hockey team, which came out on a roll.
"It's exciting, everything that's going on in this city," defenceman Alex Pietrangelo said. "It was a great day for St. Louis sports. The fans were really into it.
"I'm just glad we were able to put on a good show."
Pietrangelo had two first-period assists to pace the early scoring.
Jaroslav Halak made 28 saves for the Blues and improved to 9-3-3 against the Predators.
St. Louis has won four of its past five home openers.
Nashville, which missed the playoffs last season, is 7-7-1 in season openers.
The Blues came out aggressively, scoring three times on their first six shots.
"The first 10 minutes were ideal," Backes said. "This was a result we can love. It's just a first step, but we had a lot of guys contribute on the score sheet and off the score sheet.
"It all adds up to a pretty good team victory."
St. Louis coach Ken Hitchcock was also pleased.
"I thought that the players that have been here a while really put their best foot forward," he said. "This gives us a chance to build on some things."
Backes scored from close range at 2:05, just three seconds after Matt Cullen was sent off for tripping. Backes pounced on a shot from the blue line by Pietrangelo. The goal came 51 minutes after the final out of the baseball game.
Sobotka tallied on a break along the left wing to make it 2-0. He went by Kevin Klein and sent a backhand behind Rinne.
Oshie converted on a pass from Steen to push the lead to 3-0. Rinne was pulled after that tally.
"Obviously, I'm not happy with the result, not happy with the effort," Rinne said.
Steen scored a power-play goal at 11:16 of the second period to stretch the lead to 4-2.
Halak then made nine third-period saves to preserve the lead.
Nashville defenceman Seth Jones, the No. 4 overall pick in the draft, played 18:35 and had three shots on goal in his debut.
"I had a couple good shifts to start the game and that carried me throughout out the game," Jones said.
Jones, who was celebrating his 19th birthday, is the son of former NBA journeyman Popeye Jones. Popeye Jones, an assistant coach with the Indiana Pacers, was in attendance.
"It was a thrill, I'm just excited to be here for this," Popeye Jones said.
NOTES: St. Louis has made the playoffs in 37 of its 46 seasons. ... Nashville coach Barry Trotz is the longest-tenured head coach with the same team with 1,115 games. ... St. Louis LW Brenden Morrow fixed his work-visa problems earlier in the day and was able to play. ... Hitchcock improved to 10-3-4 in season openers.... Halak, who played in just 16 games last season due to groin injuries, last won on March 23, 2012, a 3-0 win over Edmonton.