ANAHEIM -- Jaime Barría, who has been one of the most underrated pitchers in baseball dating back to last season, fully took advantage of getting a shot at the rotation against the Red Sox on Monday.

Barría made his first start of the season while rookie right-hander Chase Silseth moved to a high-leverage spot in the bullpen, and both pitched well in their new role to help the Angels to a 2-1 win at Angel Stadium.

Barría, who isn’t fully stretched out and had a pitch-count restriction, threw five scoreless innings, while Chase Silseth threw two perfect frames to close it out. Silseth picked up the win, with Mickey Moniak continuing his hot start with a go-ahead solo homer in the eighth.

“I feel great that the manager gave me the confidence to go out there, and we got the win, which is the most important thing,” Barría said through an interpreter. “It’s important to me. That’s what I was waiting for, this opportunity. So I just have to keep doing my thing and throwing strikes.”

Barría scattered two hits and struck out six while lowering his ERA to 1.61 in 28 innings this year. Dating back to April 8, Barría leads the Majors with a 0.37 ERA in 24 1/3 innings. And going back to last season, Barría has a 2.35 ERA in 107 1/3 innings, which ranks fifth among pitchers who have thrown at least 100 innings since the start of last season, trailing only Justin Verlander, Tony Gonsolin, Jeffrey Springs and Brock Burke.

Manager Phil Nevin liked what he saw from Barría and said it’s enough to keep him in the rotation, with his next start expected to come on May 30 in Chicago against the White Sox. Barría would also likely be available in relief this weekend, if needed.

“The changeup was a game-changer and really kept them off-balance and [he] threw a lot of strikes, just like we’ve seen him do in the bullpen,” Nevin said. “It was really nice to see. I’m really happy for him.”

Barría has been incredible at inducing weak contact this season, and that was again the case against the Red Sox. Boston only managed two singles against him and he didn’t walk a batter, so he didn’t pitch with much traffic and never faced a batter with runners in scoring position.

But after a 1-2-3 fifth inning, Barría was removed, his pitch count up to 64 -- slightly above his season high of 58 over four innings against the Rangers on May 5. Barría was in line for the win, but lefty Aaron Loup allowed a run in the sixth. Still, Barría kept his scoreless-innings streak intact, as he’s thrown 14 1/3 scoreless frames dating back to April 29 against the Brewers.

“I’ve been doing a great job since Milwaukee, attacking hitters and trusting all my stuff,” Barría said. “I think that’s why they gave me this opportunity to start.”

Silseth picked up the slack with his two scoreless innings to end it. The 23-year-old opened the year in the rotation with Triple-A Salt Lake and dominated in four starts before getting called up to join the Angels’ bullpen in late April. He posted a 3.24 ERA in four relief appearances, then struggled in a start against the Orioles on Tuesday, allowing four runs over 3 1/3 innings. The Angels announced on Sunday that Silseth would be transitioning back into a relief role.

The move to the ‘pen isn’t necessarily permanent, given Silseth’s age and his pitch mix, but the Angels needed another reliever to bridge the gap between setup man Matt Moore and closer Carlos Estévez. Silseth fits the bill as a hard-thrower who can mix in his slider, cutter and splitter.

Silseth is taking it in stride, saying he enjoyed finishing things out and the adrenaline that comes with getting the final out of a close game, especially at home. He said he’s never thrown a complete game before, so it was a foreign feeling to throw the game’s last pitch. He recorded the final out against the A's on April 26, but it was an 11-3 blowout.

“If that’s where they want me to be, that’s where I’ll be and I’ll be happy about it,” Silseth said. “That was fun. It was a blast. They want me to be a power arm. I know they just want me to get outs, but I can bring that power arm. I just have to find a routine. But it was fun.”