Nolan Arenado was just a bit player at Coors Field Tuesday night. Until he swung his magic bat in the seventh inning, made the Rockies pay for Ryan McMahon’s costly error, and helped propel the Cardinals to a 9-6 comeback win over the Rockies.

Arenado, the former Rockies star third baseman, hit a three-run double off Dinelson Lamet in the Cardinals’ four-run seventh, tying the game 6-6 and turning Coors into Busch Stadium West as the red-clad fans went into a frenzy.

St. Louis won the game in the ninth against Pierce Johnson on a leadoff homer by Nolan Gorman, followed by a walk by Brendan Donovan, a sacrifice bunt by Tommy Edman and an RBI single by Paul Goldschmidt. Tyler O’Neill’s single scored Goldschmidt to give St. Louis its three-run cushion.

Truthfully, Arenado should never have had the chance to play the hero. The Rockies should have been out of the inning but McMahon botched Edman’s grounder to second to load the bases with two outs. In came Lamet in relief of Jake Bird, and Lamet promptly walked Goldschmidt for the Cardinals’ first run of the inning. Then Arenado ripped Lamet’s 3-1 fastball to the left-field wall.

This was a game the Rockies squandered, especially given the gritty performance of starter Kyle Freeland.

The left-hander prides himself on being able to out-tough opposing pitchers at Coors. Such was the case early Tuesday night. Although Freeland gave up his first two homers of the season (six hits overall) and needed 83 pitches (50 strikes) to get through six innings, he made big pitches when he had to, including groundball double plays in the second and sixth innings.

He was rewarded when the Rockies’ offense came to life in a five-run fifth inning against Miles Mikolas, giving the Rockies an ill-fated 6-2 lead.

However, Freeland’s quest for a franchise record ended quickly. He entered the game with a scoreless streak of 12 2/3 innings to begin the season. And he opened the game by striking out Donovan to extend his streak to 13 innings, tying Jason Jennings (2001) for the second-longest streak by a Rockies starter to begin a season. The streak ended with the next batter, Edman. The Cardinals’ shortstop hit a 374-foot, pop-fly homer to right. Jhoulys Chacín holds the Rockies record at 14 1/3 scoreless innings to open his 2010 season.

Mikolas pitched well until the fifth when Colorado ripped him for five hits, including a three-run homer by McMahon, followed by a solo blast by C.J. Cron to left field that measured 479 feet.