May 15—BOSTON — Members of the Cardinals had been saying for weeks that they weren’t as bad as they were playing. Of course, that sentiment carries a bit more weight coming off winning six of seven games including five of six on the road than it did in the midst of an eight-game skid.

All-Star third baseman Nolan Arenado came to Fenway Park and found his swing and regained the mojo in the batter’s box that has helped him collect five Silver Slugger Awards. Outfielder Lars Nootbaar heard the green monster calling his name and he peppered it with line drives as a table setter for an offensive explosion.

Meanwhile, right-hander Miles Mikolas repeatedly got the Boston Red Sox to hammer baseballs into the ground as though they were a road crew driving spikes into the ground.

“When things weren’t going well, it wasn’t one specific thing. It was kind of moving around,” Cardinals manager Oliver Marmol said. “All of it is coming together now overall. Defense, pitching, the hitting, timely hitting — not just amount of hit, but when it’s needed — all of it is coming together. The style of play has been closer to what we expect.”

The Cardinals smelled blood in the water and went for the throat as they pounced on the Red Sox to the tune of a 9-1 win that completed the series sweep at Fenway Park on Sunday night. They swept a series from the Red Sox for the first time in franchise history.

In the process, the Cardinals (16-25) swept a series for the first time this season, won back-to-back series for the first time this season and won five of six games on their two-city road trip.

They’ve now won six of their past seven games overall.

“Obviously, we’ve got to now take it back home and play against a division rival with Milwaukee and then LA, who is also playing good ball,” said Arenado, who went 2-for-5 with a home run and four RBIs. “But it was a really good road trip for us. We needed it. We needed to show that we can play this type of ball. Hopefully, we can continue.”

A little more than a week ago the Cardinals seemed discombobulated and off kilter in the most frustrating manner imaginable. They knew how they needed to play. They believed they had the means of playing the way the needed to play. They’d previously demonstrated an ability to perform in the desired manner and to do so consistently in the past.

Everything had seemingly been in place for weeks, yet they found different ways to let games slip through their fingers until the results unequivocally painted the picture of a bad team.

“It kind of reminds us that we are a playoff team,” Mikolas said of the past week. “Despite our bad start, the talent is there. We’re a very good baseball team. A good road trip helps, getting some big wins especially coming back late in games and showing that we have what it takes when the game is on the line and just really getting after it.”

The win for Mikolas (2-1) stopped a stretch of 16 days without a win from a starting pitcher. That had been the longest active streak in the majors.

When the Cardinals went to Chicago and Willson Contreras took center stage as one of the Windy City’s former heroes and its newest villain, that hostile environment may have provided a needed boost of energy. The Cardinals took two of three in the Windy City. Despite taking a shot on the chin in the finale, they bounced back and won all three in Boston — each of the first two in come-frombehind fashion.

A team that hadn’t won a single game when trailing heading into the ninth inning won back-to-back games against a highly regarded and accomplished closer and a Red Sox team that at least appeared capable of competing with the league’s best.

What gives? What, aside from the results, changed for the Cardinals?

“I think we’ve been playing good baseball for longer than this past week too,” catcher Andrew Knizner said. “You look at our season. Have we won some bad games? Absolutely. But we’ve lost a lot of close games. It’s not like we’ve been out of it and getting killed. We’re just not getting it to bounce our way early.

“Finally, we’ve started getting a little bit of momentum. It seems like everybody’s playing well. Guys are hitting. Pitching is good, consistent. Bullpen guys come in and do their jobs. Guys off the bench coming off are coming in and doing their jobs in big spots. ... This past series is who we are as a team.”

Arenado getting on track certainly infused the Cardinals’ offense with a jolt of life and energy that it was sorely missing as he struggled through the first week of May with a slash line of .232/.282/.326.

Arenado went 7-for-14 with three home runs and seven RBIs in the threegame series. The Red Sox scored 10 runs as a team in the series. He homered for the third consecutive game, which means half of his six home runs this season came during a three-day span playing at Fenway Park.

“I just want to do my job, drive in runs when I can,” Arenado said. “Just do what I know I’m capable of doing. I know April was a tough month. I know I’m better than that, so it was just a matter of time.”

And it wasn’t as though Arenado (2-for-5, four RBIs on Sunday) had to shoulder the burden alone. The series finale served as a great example.

Cardinals hitters combined for 14 hits, including three home runs. Paul Goldschmidt (2-for-5, RBI), Alec Burleson (2-for-4), Knizner (2-for-4, two RBIs, two runs scored) and Nootbaar (3-for-6, two doubles, three runs scored) also enjoyed multi-hit games.

Paul DeJong (1-for-5), Arenado and Knizner each bashed home runs.

“We did him kind of dirty early on in the season when he wasn’t feeling his greatest,” Nootbaar said. “I just think, as an offense, we weren’t really picking him up. That’s not fair to him. ... To see him do that, just like this team, it’s just a matter of time for that guy to get hot. He’s one of the best hitters in the game.”