BOSTON — It hasn’t taken Mike Trout long to regain his form after sitting out a month because of a bruised left knee.

Trout had three more hits Monday night, including a 454-foot homer that was the longest at Fenway Park this year, in the Los Angeles Angels’ 7-6 victory over the Boston Red Sox — his second three-hit game in three starts since returning from the injured list Friday.

“Anybody that knows Mike Trout shouldn’t be surprised,” Angels manager Ron Washington said. “Mike Trout can still do a lot of things that a lot of people can’t do. And he’s showing that.”

Trout hit a three-run homer in the first inning and singled in his next two at-bats. In the seventh, he grounded into a double play but said he had no problem with his left knee as he tried to beat the relay.

In all, the 11-time All-Star and three-time AL MVP is 8-for-14 since coming off the IL to raise his batting average from .179 to .225. It was only his second homer in 35 career games at Fenway Park.

Trout, 33, said he was able to work on his swing while he was out, though he was limited to 30-40 swings per day. The break helped him reset some bad habits he had developed, he said.

The three hits Monday gave Trout 1,675 in his career and moved him into second place on the franchise list, passing Tim Salmon. Garret Anderson holds the Angels record with 2,368.

Zach Neto homered to lead off the game, Trout added a three-run shot and Jo Adell put one over the Green Monster to make it 6-0 — all in the first. It was the first time in the 114-year history of Fenway Park that a visiting team hit three homers in the first inning, according to MLB.com.

“Anytime you set records in a stadium like this, it’s pretty special,” Trout said. “It’s pretty crazy.”