BOSTON — There are days when Tyler Glasnow makes it look so easy.When he uncoils that long frame that makes him seem right on top of the plate, makes the curveball spin and the fastball sizzle, dominates hitters to where they don’t seem to have much of a chance.He has teased and flashed that form at times, especially after being acquired by the Rays on July 31 from the Pirates, with outfielder Austin Meadows and prospect Shane Baz, for Chris Archer in what might turn out to be one of their greatest heists.Now it seems to be the norm.Which would really make Glasnow extremely special.Sunday’s start was his sixth of the season, and he was on his game again, leading the majors-best Rays to a 5-2 win over the Red Sox, and a sweep of their rain-shortened two-game series.That he was sharp, cruising through the first five innings while mixing in a changeup and allowing Boston just two runs while working into the seventh, was certainly impressive.“I thought he was outstanding,’’ manager Kevin Cash said. “He kind of picked up where he’s been all season. To limit that offense like that in this ballpark is really challenging. And it speaks volumes to how good his stuff was.’’That he could maintain this level of performance, and anything even close to the results, 5-0 with a 1.75 ERA thus far, would be truly remarkable.And yet, his Rays mates say, very much realistic.“Yeah, he’s this good,’’ pitching coach Kyle Snyder said. “He’s always been really good. I think he’s finally started to realize it. The confidence is starting to grow. The approach is just a little different than probably what he’s done in the past just in terms of trusting his stuff.“His stuff has grown so much the last couple of years that he’s able to do that. He’s able to take an all-power approach and really limit the art to what he does.’’Catcher Mike Zunino, who saw his share of elite arms in Seattle, is also a believer that this is the real Glasnow.“I don’t see why not,’’ he said. “Obviously that’s a high ask. But he’s worked extremely hard and as long as he continues to trust his stuff, and his health stays in the right direction, he’s got the stuff to absolutely last.’’Glasnow, 25, was 1-5, 4.20 in 11 starts last season for the Rays after they got him and returned him to the rotation; the Pirates had dumped him to the bullpen.While Glasnow worked hard this winter to refine his pitches and get his 6-foot-8 body into even better shape, the biggest difference has been in his mental game.“Just mentality and confidence,’’ he said. “Just going out and believing in my stuff. Just really going out and competing.’’Glasnow deserves the credit for making the change, but some of the influence came from rotation mates Charlie Morton, whom he knew from Pittsburgh, and Blake Snell.“The mind-set stuff is very, very evident to me, how locked in he is during his game,’’ Snyder said. “He’s taken it to another level. The conviction, in the body language, you can see all of that.’’Glasnow showed it all Sunday, especially after being handed a 2-0 lead in the first, thanks to Daniel Robertson’s first homer of the season, then having it doubled on another big hit by Yandy Diaz.Glasnow fired blanks the first five innings, pitched into and, thanks to a longer leash from Cash this Sunday than last, out of trouble in the sixth. He got the first two outs of the seventh for a solid 102-pitch outing. Adding the changeup as a new weapon since he was facing the Sox for the second straight start was a crafty move, too.“He threw a changeup for strikes against lefties. He has that heater with movement against righties. He was getting a lot of swings,’’ Boston shortstop Xander Bogaerts said. “He’s a young kid, this guy. He’s had good stuff against us every time.”Glasnow isn’t going to have all good days over his 32-33 starts. And there will be some games when he pitches well yet bad things happen. But if this six-game start truly is a glimpse of what’s to come, the Rays would be ecstatic.“Ever since we acquired him you’ve seen continual progress,’’ Cash said. “This year he’s just taken off. He’s pretty special when he’s out on the mound. He made really good hitters have difficult at-bats against him.“I think he’s totally capable of doing this. I don’t know if it’s ever fair for the expectation of any pitcher or anybody to just go out and dominate the way he has. We have to allow for hiccups here and there. But I know when he’s on the mound or when it’s his day to start, we’re feeling really good about ourselves. And I think that’s the best way you can really validate the performance, the previous performance, and what you think is going to take place.’’ Contact Marc Topkin at email@example.com . Follow @TBTimes_Rays.