ANAHEIM -- It is easy to forget all these months later that the Red Sox signed Kiké Hernández to be their second baseman. Due to the in-season construction of the roster, Hernández has instead emerged as their primary center fielder and that’s been one of the most significant developments of the season.

Hernández was at it again on Monday night at Angel Stadium, using his glove and arm to help his red-hot team to a 5-4 victory in the opener of a three-game series.

Making his 50th start of the season, compared to 16 at second base, Hernández raced back to the wall for a fly ball hit by Luis Rengifo that looked like trouble in the second. But Hernández got back in time, jumped as high as he could and came down with the baseball. At the very least, it would have been a run-scoring double if Hernández wasn’t able to come down with the ball. There’s also a chance it could have been a two-run homer.

He wasn’t done. In the sixth, with the leadoff man at first and nobody out, Max Stassi smashed one into the gap in right-center. Hernández fired a strike to second base, where Xander Bogaerts tagged out Stassi.

The Red Sox rode their stingy defense to their 10th win their last 11 games -- and 15th in the last 20 -- to maintain a 4 1/2 game lead over the Rays in the American League East.

“Kiké, he made two good plays and I think that was a key to win the game,” said winning pitcher Martín Pérez. “The first catch in the second inning. And in the sixth, he got a good throw to second and got the guy out.”

It was the MLB-leading 28th outfield assist of the season and second of the night for the Red Sox, as left fielder Danny Santana fielded a single by Shohei Ohtani and fired a bullet to the plate to nail Jose Rojas, who was originally ruled safe in the fifth. Thanks to a challenge by Sox manager Alex Cora, that call was reversed.

“It was part of the scouting report coming in. It's not something that surprised us,” said Angels manager Joe Maddon. “And I love it because it illustrates how important outfield defense is. I think it's one of the more underrated parts of the game. When you have technically good outfield defense and guys know what they are doing and they can throw well and accurately, you see what can happen. It's a huge part of the game, and they do it really well."

With Alex Verdugo, Hernández and the cannon-armed Hunter Renfroe getting most of the reps in the outfield, opponents should think hard before running on the Red Sox. Of late, others have also stepped up with key assists, including J.D. Martinez and Santana.

“The way [Hernández] has been playing center field is above average. The fact [that] they have to respect our arms, all of them out there, we can shut the running game down because of who they are, it’s a plus for us,” said Cora.

One of the key reasons Cora has stuck with Hernández so much in center is because of how good Christian Arroyo has been at second base.

That was demonstrated at a most critical point in this one. With two on and two outs in the bottom of the ninth, megastar Ohtani came to the plate looking for the best way possible to cap his 27th birthday.

“I mean, I was trying to avoid that ever getting to that point. I had in the back of my mind, ‘Don’t let Ohtani come up.’ Of course, it happens,” said Red Sox reliever Adam Ottavino. “In the moment, I’m ready for battle. It’s a fun situation.”

Behind in the count 3-1, Ottavino threw a slider that caught too much plate. Ohtani belted it 101.9 mph into the second-base hole. Per Statcast, the well-struck grounder had an expected batting average of .910. Fortunately, Arroyo was shifted into the perfect spot in short right field and kept the laser-beam in front of him. He picked it smoothly on the short hop and fired to first to complete the exciting win.

It was a sweet comeback from the 10-day injured list for Arroyo, who also smashed a solo homer in his first at-bat since June 20.

“That play by Christian at the end was great,” said Cora.

Of course, the night wouldn’t be complete without some more heroics from Rafael Devers. The first-time All-Star mashed his 21st homer of the season, a two-run shot to right-center in the fourth as part of a three-hit, three-RBI night.

“I think I always said when he dominates the strike zone the way he’s dominating right now, he’s that good,” said Cora. “He hits a home run to right-center and then he sits on a fastball and goes the other way. He’s just a pure hitter. Sometimes I don’t want to tell him to be more selective because it might work against him.”

These days, just about everything is going for the Red Sox rather than against them.