BOSTON -- The good news for the Angels is they’re unlikely to play a game this sloppy the rest of the season.

But the bad news is that their series of miscues -- three errors, four unearned runs allowed, two hit batters, a wild pitch, a run-scoring passed ball and going 1-for-14 with runners in scoring position -- all added up to a frustrating 5-3 loss to the Red Sox in the series opener at Fenway Park on Friday night.

“We pitched way too well to be in the position we were in late in the game,” said Angels manager Phil Nevin. “We just made uncharacteristic mistakes. And if you do that at this level, you’re going to get the result we just did. We’re better than that. We all know that. Mistakes happen. Just one of those nights.”

Third baseman Anthony Rendon was responsible for two critical throwing errors with two outs in both the fourth and sixth innings. And he took full responsibility after the game, indicating both throwing mistakes were on him.

“I didn’t have the best grip,” Rendon said. “I got to hit him in the chest. It was not my day today.”

After lefty Patrick Sandoval cruised through three scoreless innings, including getting helped by a tremendous diving play by Rendon to end the third, he ran into trouble in the fourth after Luis Rengifo opened the inning with a fielding error.

Sandoval uncorked a wild pitch before giving up an RBI double to Kiké Hernández to get the Red Sox on the board. Sandoval later appeared to get out of the inning without any more damage, as he induced a routine grounder from Yu Chang with runners at first and second with two outs. But Rendon’s throw got away from first baseman Jake Lamb, who couldn’t make the scoop, allowing a run to score.

“It’s definitely frustrating, especially after saving that one in the hole,” Rendon said. “You’re doing it for Sandy. You’re trying to take away extra-base hits and extra hitters. It sucks, but you just have to do better next time.”

It also prolonged a laborious inning for Sandoval, who had to be taken out after having thrown 90 pitches, including 36 in the frame. Sandoval also was visited at the mound by Nevin and assistant trainer Matt Biancuzzo during the inning but indicated after the game he was just fine, saying they just checked on him after they saw his fastball velocity decrease on a 3-0 pitch.

“I felt pretty good early on, but later in the game, I kind of lost my feel for the zone a little bit,” Sandoval said. “I have to make better pitches in bigger moments. Three walks is frustrating. It’s not a good recipe to win.”

Right-hander Jimmy Herget replaced Sandoval and escaped a jam with the bases loaded, but when he went back out for the fifth, he had to face at least two batters because of the three-batter rule. He struck out Rob Refsnyder, then gave up a solo homer to Rafael Devers on a first-pitch curveball that gave the Red Sox the lead.

“Jimmy did a great job of getting out of that [jam], but he had to go through a tough part of the lineup,” Nevin said. “Devers is not a great matchup there but we were kind of handcuffed.”

The sixth was just as ugly for the Angels, as lefty Aaron Loup hit Boston’s No. 8 and 9 hitters to start the inning. Afterwards, Loup settled down to get Alex Verdugo to ground out before getting a key strikeout of Justin Turner. He then induced another grounder to third from Refsnyder, but Rendon made another throwing error that brought Lamb just off the bag at first.

It allowed a run to score. Another later came home on a passed ball from catcher Logan O'Hoppe to give the Red Sox a three-run lead.

Despite all of their defensive miscues, the Angels had several chances to get back into the game or take the lead back after scoring twice in the first on a two-run double from Hunter Renfroe. But Renfroe’s double was their lone hit with runners in scoring position, as they squandered scoring chances in the third, fourth, fifth, sixth, seventh and eighth innings.

​​“We hit a couple of balls hard and we really got a lot of guys on late in innings,” Nevin said. “But we did get the first two batters on twice and we hit into a double play once and we miscommunicated a bunt sign on the other.”