BOSTON (AP) -- Mike Trout can cross Fenway Park off his home run to-do list.
With his 428-foot drive over the Green Monster in the sixth inning, Trout has now homered in every American League ballpark. He had played 21 games in Boston without connecting.
''I didn't think about it,'' Trout said. ''I think I got reminded about it every time I've come here.''
After two at-bats against Red Sox starter Rick Porcello in which he struck out and grounded out, Trout came up again and Porcello missed on a fastball that went straight over the middle of the plate.
Trout made him pay for it.
''I hit it good,'' Trout said. ''He pitched me tough my first two at-bats. I was looking for a pitch to hit and I got one.''
The homer was Trout's 39th this season, tying for the major league lead with Milwaukee's Christian Yelich.
Trout was replaced in the seventh, having been hit in his shoulder by a pitcher earlier in the game. Trout was feeling fine.
Justin Upton added a three-run homer in the first inning.
The Angels scored seven times in a sloppy seventh inning by Boston in which it issued two walks, hit two batters and gave up four singles. The Red Sox also had an error and a passed ball.
The loss denied Boston its first three-game win streak since it won three straight games against the Yankees last month. It's also yet another head-scratching setback for the defending World Series champions, who looked to be turning a corner following an eight-game losing streak last month.
''We'll keep working, we'll keep going,'' manager Alex Cora said. ''There were some positives, but obviously at the end we need results as a team.''
Taylor Cole (2-3) pitched 1 2/3 innings of scoreless relief to pick up the win.
Porcello (10-9) took the loss, giving up both home runs. He lasted five innings, allowing five earned runs off five hits, walking one and striking out four.
''Sixth inning I throw three pitches, give up two runs. It's tough, I got to be better,'' Porcello said.
Porcello retired 14 batters in a row after Upton's homer, but for the first time in several starts didn't get run support.
Porcello entered the night having won five of his previous six starts despite allowing 26 earned runs in 34 1/3 innings. But he had also benefited from a major-league-leading 7.3 runs per start by Boston's offense.
The runs weren't there for him on Saturday.
The Red Sox left 11 runners on base after outscoring the Angels 19-4 in the first two games of the series.
Angels: Shohei Ohtani threw a 40-pitch bullpen session Saturday and said his velocity is improving. ''Before I get into the breaking balls, I need to hit my velocity, but I think we're getting close,'' Ohtani said through a translator. He reached as high as 82 mph and joked that put him at ''probably about 82 percent'' of his goal. Angels manager Brad Ausmus is pleased at the progress. ''He was good. No complaints, so that was good,'' he said.
Red Sox: 1B/OF Steve Pearce (low back strain) hit in the cage and ran lightly in the outfield. He said he can do everything but run sprint after being set back by a partially torn ACL. ''In this game you have to be able to run and you need to be able to burst and that's what I'm having trouble doing right now,'' he said. Pearce said the ACL injury won't require surgery and is being treated with exercise as he tries to build the muscles around it.
The Angels improved to 38-18 when scoring first this season. They have scored three or more runs in the first inning 11 times this season, going 8-3 in those games.
Angels: LHP Patrick Sandoval (0-0, 3.60 ERA) is making his second appearance for the Angels this season after getting a no-decision in his major league debut at Cincinnati.
Red Sox: RHP Andrew Cashner (10-7, 4.68 ERA) is a win shy of matching his career high of 11, set with the Rangers in 2017. He's pitched six or more innings in each of his last three career starts against the Angels.