That he’s the fit the Cardinals needed was clear quickly.

In Arenado’s first three trips to the plate as a Cardinal there was a runner in scoring position, a chance to announce his authority with what they’ve been missing, and only a diving catch in center kept him from making the most from his first, second, and third impressions. Arenado had two hits in his first two at-bats, Paul Goldschmidt scored three runs by the end of the fourth, and the Cardinals offense carried opening day with a 11-6 victory Thursday against Cincinnati at Great American Ball Park.

A lineup that stalled too often right to the shutout ending of their 2020 season got jolts early from their established cornerstone All-Stars. Goldschmidt finished the game with four hits, including two doubles.

And the exclamation points came the young outfielders.

Rookie Dylan Carlson punctuated the Cardinals’ six-run first inning with a three-run homer, and in the fourth Tyler O’Neill extended the lead with a two-run bolt.

“It’s the emergence of talent,” said John Mozeliak, president of baseball operations, about the young outfielders, before the game. “The emergence of impact.”

The emergence proved essential, for Day 1.

The onrush of offense allowed starter Jack Flaherty and a parade of relievers to pitch with a cushion they only allowed to be threatened, never overtaken. Flaherty did not qualify for the win in his second consecutive opening day appearance as he came two outs shy of five innings. His pitch count was exhausted – but so too was his effectiveness in the fifth inning. The Reds got two walks, an RBI single, and loaded the bases on the righthander in their third look at him. Flaherty lefty the bases-loaded jam for lefty Tyler Webb to wiggle free, and he did after allowing only a sacrifice fly.

Flaherty allowed six runs on six hits and two walks. He struck out two, and it was after a run scored in the first inning on a wild pitch that he found his best groove.

Pitching with that substantial lead, Flaherty retired eight of the next inning batters after a leadoff double from Reds Jesse Winker to start his season. Flaherty allowed two home runs – to Nicholas Castellanos and Eugenio Suarez – but neither put the Cardinals’ lead in much jeopardy because the Cardinals added on to that early 6-0 runaway.

The Reds helped.

Calling one of the coziest places in baseball home for half of the season, Cincinnati has the luxury of conjuring offense from Great American Ball Park, and that can allow them to take some chances with their roster. They have evidently sided with trying to outrun teams this season vs. holding teams back — it’s basically a fastbreak approach to baseball, and it means at times the Reds defense is … porous. Shortstop Suarez, a third baseman previously, committed two errors in the first two innings, and had another non-play that prolonged an inning.

His error in the first became an RBI for Yadier Molina, and set the bases for Carlson’s three-run homer. In the second, Suarez’s throw to first got past Joey Votto and allowed Goldschmidt to reach second on his infield single. That put him in scoring position for Arenado’s single up the middle.

That was Arenado’s first RBI as a Cardinal.

It came on his second single as a Cardinal.

That came in his second at-bat of the Cardinal.

He got several firsts of the way Thursday.

In the first inning of Arenado’s first game of his first season with the Cardinals, it took his teammates 13 pitches to open that six-run lead. Luis Castillo retired the first batter he faced, leadoff hitter Tommy Edman, on a groundball. Goldschmidt followed with a ball off the top of the right-field fence. The ball came so close to being a home run that it took 2 minutes, 15 seconds for the umpiring crew to review the video and determine it was a double.

The Cardinals were four minutes into their season and they had a runner in scoring position – and half of the season had been spent waiting on a replay.

Arenado and cleanup hitter Paul DeJong followed with singles, and that began a run on Castillo. The Cardinals had a baserunner reach on four consecutive pitches.

1. DeJong’s RBI

2. A pitch hit O’Neill.

3. Molina’s RBI on an error.

4. Carlson’s home run.

Carlson, 22, is the youngest Cardinal to hit a home run on opening day since 1936. His homer clanged off the right-field foul pole to avoid any need for a replay.

The Cardinals turned to late-inning, high-leverage, and April closer Alex Reyes to complete game, during which they never had a lead smaller than four after the top of the first inning.

The Cardinals improved to 60-68-2 on opening day.

This was the Cardinals’ 19th time opening the season against the Reds, and they improved to 11-8 against their longtime National League rival.