It’s not how you start, it’s how you finish.

Such was the case for Ranger Suárez and Kyle Leahy, who had polar opposite starts, and for the Boston Red Sox, who scored a season-high seven runs in Saturday night’s 7-1 win over the Cardinals in St. Louis.

Leahy started strong but it was Suárez who finished strong. The Red Sox southpaw recovered from a lengthy first inning in which his normally-impenetrable composure showed the slightest cracks, to turn in six shutout innings of three-hit baseball.

Suárez entered Saturday having yielded four earned runs apiece in each of his first two starts of the year, neither of which lasted more than 4 ⅓ innings. Therefore his frustration in the first inning, which required 27 pitches and could’ve ended much sooner, wasn’t altogether surprising. Suárez’s third pitch to No. 3 hitter Jordan Walker was a strike at the on the outer corner of the bottom of the zone, but catcher Carlos Narváez didn’t request a challenge. (The Red Sox have told pitchers not to challenge.) Thus the pitch remained Ball 2, and Suárez ultimately walked Walker on six pitches. After Suárez walked No. 4 batter Nolan Gorman, pitching coach Andrew Bailey came out to the mound to help his starter reset.

Suárez only faced one more batter in the first, but Ramón Urías didn’t go quietly. The Cardinals first baseman successfully overturned a Strike 3 call on Suárez’s fifth pitch, though it only prolonged the inning by one pitch, as Urías swung and missed to end the first.

Leahy, meanwhile, plunked Willson Contreras to begin the second inning, and still needed just six pitches to get through his second consecutive 1-2-3 frame. The Red Sox erased their leadoff baserunner with a double play in the third inning, too, saw the Red Sox erase their own leadoff baserunner (Marcelo Mayer, single) with a double play (Narváez) and go 1-2-3.

But the third inning took Leahy 17 pitches, and then Boston broke through in the fourth. They forced Leahy to throw 35 pitches, and took a 2-0 lead on Contreras’ 2-RBI double, which scored Roman Anthony (leadoff walk) and Jarren Duran (one-out single). The Red Sox went so far as to load the bases, before Narváez flew out to center to end the frame.

“It was good to put the ball in play … especially to start a rally,” Contreras told reporters postgame.

The fourth proved to be the end for Leahy, who wasn’t allowed to face the Red Sox order a third time when the lineup turned over in the fifth inning. He exited charged with two earned runs on three hits, three walks, and two strikeouts, and took the loss.

While Leahy’s smooth sail turned into a grind, Suárez was locking in. He issued no further walks after the two in the first inning, and racked up six strikeouts. He retired 14 of his last 15 batters. After the 27-pitch first inning, Suárez got through the remaining five on just 57 pitches.

“I mean, he can pitch man,” manager Alex Cora told reporters. “He had one bad inning against San Diego (in his last start). You have to be realistic, too. The numbers are the numbers, and I know it doesn’t look great, but it was one bad inning.

“And then today he moved the ball around. It seems like his arm was a lot quicker than the first two (starts). He tells me that he feels better.”

Greg Weissert, Danny Coulombe, Garrett Whitlock and Ryan Watson pitched the rest of the way. Aside from a solo home run by Jordan Walker, the Cardinals were kept off the board.

After two missed opportunities with the bases loaded, third time was the charm for the Boston bats. Trevor Story led off the top of the ninth with his first walk of the year. Cardinals righty Matt Svanson faced seven more batters, and gave up five earned runs, on six consecutive singles to Narváez, Rafaela, Anthony, Caleb Durbin, Duran and Contreras.

With a six-run lead, Aroldis Chapman got the night off, and Watson worked around a one-out single (Fermín) and two-out hit-by-pitch (Nathan Church).

The Cardinals struck out eight times, drew three walks, and managed just five hits in the contest. The Red Sox only struck out six times, drew five walks and tallied 10 hits, including two apiece by Duran, Contreras and Narváez.

“We talk about bringing the energy no matter what happens, we talk about fighting every at-bat no matter what happens,” Contreras said. “We’re not looking to hit homers, we’re looking to put the ball in play. And then if we do damage, we do damage.

“But I think we have to start, at some point, like putting the ball in play more. And we did in the ninth, and it worked out. I think the homers are gonna come, the doubles are gonna come, but if we stay short to the ball, we stay trying hit our singles and our walks … going to be OK.”

Boston’s first game of the season with more than six runs scored evened the series 1-1. The Red Sox and Cardinals wrap up Sunday at 2:15 p.m. ET.

Double trouble

In addition to five successful ABS challenges by Cardinals players, the bottom of the seventh yielded a unique scene: a double overturn.

Left-fielder José Fermín was originally sent to first base on a one-out hit-by-pitch, which Cora got overturned.

But Cardinals skipper Oli Marmol challenged, too, and Fermín was sent back to first base as umpire Bill Miller determined catcher interference by Narváez.

‘Bring the energy’

Red Sox players discussed shifting their collective mindset before Saturday’s game.

“I think the energy is way higher than before. That’s what we noticed tonight,” said Contreras. “We have to come out here with (hunger). And we have to play a little bit angry, too.”

“We talked today about just having more energy than before, and we did,” he elaborated. “And that’s what happens when you try to put your focus on having good energy and not trying to seek results.

“You take a lot of pressure off of your shoulders, and you’re not sitting on the bench just thinking about getting base hit, or getting a double or getting a homer. Just like, bring the energy and whatever’s going to happen is going to happen. But just stay positive and do our best to get on base.”

Facts and figures

Though the Red Sox are 5-9 on the season, they have won three of their last four.

Saturday marked Boston’s first time scoring more than six runs in a game this season. They improved to 5-4 when they score first, 3-4 when they score at least four runs and 4-4 when they don’t hit a home run.

The Red Sox are 15-15 all-time against the Cardinals in the regular season. Saturday also marked the 360th interleague win in Red Sox history, the most in Major League Baseball.