PITTSBURGH -- Kutter Crawford found himself in the first tough situation of his start on Saturday against the Pirates in the fourth inning. Ke’Bryan Hayes hit a leadoff double and Joey Bart drew a one-out walk. It was the first time Crawford had allowed two baserunners to reach base on the day.

Rowdy Tellez stepped to the plate, took two pitches, and then tried to lift a middle-cut splitter from the Red Sox right-hander. Instead of finding the barrel, it barely grazed the bat, spun up and over the Pirates first baseman’s head at an odd angle and was caught by Reese McGuire near Boston’s on-deck circle.

Tellez slammed his bat down in frustration and snapped the handle off. Crawford ended up allowing a run that frame, but it was the only one he would allow all day en route to Boston’s 4-2 win over the Pirates at PNC Park.

And this season, Crawford has made a lot of batters feel like Tellez.

Crawford now owns the best ERA mark by a Red Sox starting pitcher (0.66) since Roger Clemens produced a 0.66 ERA through his first five starts in the 1991 season. Saturday marked the most traffic he had allowed in a start, with seven hits and three walks permitted, but it only gave us a chance to see his clutch-time form put into practice.

“I like these starts a lot,” Crawford said. “I take pride in competing and trying to work out of situations like that.”

Crawford was the only pitcher in Red Sox history (excluding openers) to allow one or no runs and three or fewer hits in each of his first four starts of the season. But that streak was snapped, as he labored more than he had in any other start this season, reaching 100 pitches for the first time in 2024 and allowing seven hits.

However, Crawford also drew 17 swings and misses, which are a season best and tied for the second-best mark of his career. Most came on his namesake pitch, the cutter (seven), but he found fairly consistent results across the board on his offspeed pitches.

Two of the biggest whiffs came in the fifth inning after Crawford loaded the bases with only one out, trying to protect a one-run lead. He settled himself down during a mound visit, then proceeded to strike out Jack Suwinski and Bart to end the threat. He emphasized the moment with an animated celebration and yell.

Three batters later, Masataka Yoshida rewarded him and put the game out of reach with a two-run homer.

What’s made Crawford so unbelievably effective to begin 2024?

A part of it may be his funky windup, where he hitches his arm right at the moment you’d think his arm would start moving forward.

“He’s just trying to throw you off timing. Timing is hitting,” said Pirates outfielder Bryan Reynolds. “When I face somebody like that, I just get ready extra early then sit there and wait for it. It was effective and messed with our timing today.”

But mostly, it’s the growth he’s shown since he made his MLB debut in 2021. In the beginning, the Red Sox tried to use him as a reliever and a starter, which Cora admits was a bit of a mistake in hindsight.

“We made him a reliever. We made him a two-pitch pitcher. That was wrong from our end,” Cora said. “This guy is a starter at the big league level.”

Cora has now made clear his faith in the pitcher who went from being seen as maybe a two-pitch reliever into a five-pitch starter with records to his name. In fact, Cora came out for a mound visit with two outs in the sixth inning, after Crawford had just walked Oneil Cruz with two outs.

But unlike most manager’s visits to the mound, which end in a hook, this was simply him reaffirming that the next guy was Crawford’s to get.

“I think [Cora] watching me pitch over the last couple of years and seeing me develop, maybe that helped persuade him to leave me out there,” Crawford said.