PITTSBURGH – All good streaks come to an end. And Blaine Boyer's moment came Wednesday.

Riding a wave of 17 ⅔ scoreless innings, Boyer fired a 93 mile-per-hour fastball at Andrew McCutchen and watched the Pirates star deposit it in the center field stands. The solo home run tied the score and forced extra innings.

But the Twins got a home run from Joe Mauer in the 13th inning to win 4-3, and Boyer was off the hook.

The end of his scoreless streak does not tarnish his full body of work this season. After getting off to a horrible start to his Twins career, Boyer rebounded to take over the eighth-inning setup role while Casey Fien recovers from a shoulder strain.

The bullpen, led by Glen Perkins' major league-leading 15 saves, has helped the Twins go 21-1 when leading after seven innings. Boyer has had a huge hand in that.

"Oh my, has he been a godsend," Twins pitching coach Neil Allen said.

The smiling, bearded Boyer is 1-1 with a 2.49 ERA through 21 ⅔ innings. His seven holds tie him for sixth in the American League.

He signed with the Twins as a minor league free agent during the offseason — turning down about five other teams. He spent 2014 with San Diego, where he was 0-1 with a 3.57 ERA. He held righthanded hitters to a .178 batting average, so that was expected to be his niche with the Twins. But the opposite has happened. Righthanded hitters are batting .340 off of him — but lefthanders are batting just .111.

"I've been able to keep them off balance," Boyer said of his sudden dominance of lefties.

Boyer throws a fastball, curveball and slider, and Allen has encouraged him to use his off-speed pitches more and more to get hitters off balance.

"Right now he's throwing his off-speed when behind in the count," Allen said. "He's got confidence right now. Sure he hit a bump coming out of the gate, but, [from] spring training, that's the guy that we saw. That guy is back now and that has been huge for us."

Early 15.00 ERA

Boyer's confidence took a hit when he posted a 15.00 ERA through his first four outings. The capper was a two-run homer by Gordon Beckham during a 6-2 loss to the White Sox on April 12. Avisail Garcia stole second base on him in that game, highlighting another issue — Boyer's inability to hold runners on base.

The problem was mechanical, as Boyer was rushing his delivery with runners on base.

"I was trying to be even faster than I was, and I feel like, somewhere, I just kind of got lost," he said. "Once I made my adjustment everything sped up anyway."

There was a mental component as well, and Boyer credits bullpen coach Eddie Guardado with helping him relax and focus.

"Eddie knows exactly what it's like to be in our position," Boyer said. "He's had ups and downs. He's closed, he's been a middle guy. He's started. He's experienced a lot. I think when I was going through what I was going through, he was basically telling me, 'Clear your head, man, understand that we're here for a reason and our first instinct is to put more pressure on ourselves, especially when we're going bad.'

"He's just really good at lightening the mood."

The turnaround

Boyer didn't appear in a game for five days. When he did, he pitched 1 ⅓ scoreless innings against Cleveland on April 17. And that was the start of his scoreless streak.

With Fien beginning a minor league rehabilitation stint this week, he eventually will return to his setup role. That will leave Boyer to handle the seventh inning — or the eighth if Fien needs a break. And that's a positive development for a bullpen that was a question mark at the beginning of the season.

"You look for people to step up," Twins assistant general manager Rob Antony said. "when Fien went down we gave him that opportunity and he rose to the occasion. He had a pretty good year last year, so I don't think it's a complete surprise, but he's on a good roll right now.''