On cue, that old Blackmon magic showed up Tuesday night at Coors Field, but the Rockies’ chances of beating the Cardinals disappeared with the return of late-inning pratfalls.

St. Louis scored a run in the seventh and four more in the eighth to turn a tight game into a 7-3 cruiser.

A day after announcing his retirement, 14-year veteran Charlie Blackmon swung his magic wand and gave the Rockies a short-lived 3-2 lead in the fifth with an RBI triple into the right-center gap.

Blackmon is 38, but he still has the wheels of a much younger player, and he burned up the basepath on his way to third.

The triple was Blackmon’s team-leading fifth of the season and the 68th of his career, the most in franchise history and the most among all active major leaguers.

Blackmon also led off the eighth with a double, but the Rockies failed to bring him home.

The Cardinals turned four hits and a walk into four runs in the eighth off right-handed relievers Angel Chivilli and Jake Bird. The clutch hits were RBI singles by Jordan Walker and Victor Scott off Chivilli and a two-run double by Masyn Winn off Bird.

St. Louis tied the game, 3-3, in a bizarre seventh inning.

Rockies starter Ryan Feltner, working on a fine game, left with an apparent injury while facing leadoff hitter Lars Nootbar.

Right-hander Victor Vodnik replaced Felnter in the middle of the at-bat and walked Nootbar before striking out Walker.

Then pinch hitter Matt Carpenter crushed a double to right-center, advancing Nootbar to third. Winn hit a shot back to Vodnik, who caught Nootbar in a rundown, but the Rockies botched it when they failed to tag Nootbar. As Nootbar scampered back to third, Scott (pinch-running for Carpenter) scooted back from third base to second, and Winn ended up on first on a fielder’s choice.

The Cardinals then cashed in on Alex Burleson’s RBI groundout to short.

St. Louis struck first when they rocked Feltner for two runs on four hits in the third. Michael Siani led off with a single and stole second. Siani waltzed home on Winn’s two-run homer to left.

The inning could have gotten away from Feltner — he gave up a one-out single to Paul Goldschmidt and a two-out single to Brendan Donovan — but Feltner struck out Nolan Arenado and got Ivan Herrera to fly out to right to put down the St. Louis rally.

Colorado countered in the bottom of the third on Aaron Schunk’s solo homer off right-hander Michael McGreevy. It was Schunk’s second homer.

Feltner made another quality start, his third straight in September. He pitched six innings, allowing two runs on six hits. He walked only two. He has a 2.22 ERA in September.