PITTSBURGH -- There is no argument regarding how well Boston’s starting pitching has been this season. And if their Opening Day starter keeps trending in the direction he has to start the season, the rotation could remain one of the best in the Majors despite the injuries it has had to endure in April.

Brayan Bello held the Pirates, who had collected eight double-digit hit games in their first 19 of the season, to just one hit, blanking them en route to an 8-1 win at PNC Park on Friday night.

Outside of an uneven start in Oakland, where he allowed four runs in five innings, Bello had been solid ahead of his outing vs. the Pirates, but he had yet to complete six innings as he had done in more than half of his starts last season. However, he finally got through the sixth frame in his fifth start -- exactly the same as he did in 2023.

“He was amazing,” manager Alex Cora said.

A huge help was that Bello’s changeup was particularly sharp. He threw it 40 times, and he tied his career-high whiff mark on the pitch with nine and his career-best called strikes plus whiffs total with 14.

It was a secondary offering in his first three starts of the season, but in the past two he’s turned to it the most of his three pitches. In turn, his strikeout numbers have jumped from 11 in his first three turns to 15 in his past two.

“I feel like today, I was able to locate the changeup way better than in any of my previous outings,” Bello said through interpreter Carlos Villoria Benítez. “So yes, I felt like today was the best that I could have had with the changeup.”

When your changeup is as good as Bello’s, it’s easy to turn to it so often, but another key for Bello was that his fastball command was strong enough to make the batter guess.

“He knew what he wanted to do,” Cora said. “His velocity was up, too. It was 96. He was able to use his changeup a lot, but at the same time, keep them honest with the fastball.”

It helped him massively to have the run support that the Red Sox batters provided. They slugged four home runs while he was on the mound, and the damage proved to be unrelenting against the Pirates’ pitchers. Boston scored runs in five different innings. But as the number in the runs column grew for the Sox, the focus on the zero in Pittsburgh’s run column only increased for Bello.

“Every time they scored a run, I tried to talk to myself and say, ‘Next inning, I need to keep it at zero. I need to get my guys back to hitting,’” he said.

Even Cam Booser, whose long journey to his MLB debut stole the show on Friday, had to note that his whirlwind day became that much better seeing how Bello “absolutely pitched wonderfully.”

The story of the box score may have been the Red Sox’s homer happiness, but the pitching has been the story of the season. Boston’s starters have by far the best ERA in MLB (1.72 in 110 innings) even as they await the return of Garrett Whitlock (left oblique strain) and Nick Pivetta (right elbow flexor strain). There’s still a TBA for Sunday in the Pirates’ series, which Cora indicated Josh Winckowski is a strong candidate to fill, though no plans have been determined yet.

But if Bello can go deep, Kutter Crawford can continue to amaze and Tanner Houck taps into his complete-game form from his last start, the Red Sox’s rotation can carry the team to better outcomes.