He said he felt good between starts and his offense even gave him an immediate two-run cushion Tuesday night to put him in a nice position.
Then the Athletics came out swinging, Weaver surrendered a three-run homer to Brett Lawrie and the damage was done in a 6-2 loss to Oakland.
Weaver, an 18-game winner last season, fell to 0-3 to start a season for the first time.
"It’s definitely frustrating. I’ll go out and battle through my next start," he said. "I felt pretty good in between starts. It just didn’t carry over into the game."
A’s right-hander Sonny Gray kept slugger Mike Trout off the bases all night and struck him out twice to beat the Angels for the second time in seven days, snapping the A’s season-high four-game losing streak.
Weaver retired 12 straight batters after Lawrie’s second home run of the year before Marcus Semien’s two-out single in the fifth.
"He’ll get it figured out," Angels manager Mike Scioscia said. "His stuff is really not too far off from when he won 20. You can still see the upside with Jered. He know’s how to get through the game. He knows what he’s doing."
The Angels opened a six-game Bay Area road trip that includes a weekend interleague series against the World Series champion San Francisco Giants at AT&T Park. Los Angeles is in a stretch with 25 straight games in its home state.
David Freese hit a two-run single on his 32nd birthday in the first inning but the A’s answered immediately in the bottom half. The Angels were limited to three or fewer runs for the seventh time in 10 games after they led the majors in runs with 773 in 2014.
Facing Oakland for his second straight outing, Weaver allowed six runs and six hits in seven innings, struck out one and didn’t walk a batter for the fourth time this season.
Angels starting pitchers had gone 3-0 with a 1.50 ERA with 30 strikeouts over their previous six games.
"It’s not the way I wanted to start it off," Weaver said. "The inning just blew up on me. I was able to settle in after that but it was too late."
Oakland won for the first time this season when its opponent scored first.
Gray improved to 4-1 over seven starts and eight career appearances against the Angels, who played their first game since the trade of left fielder Josh Hamilton to Texas became final during Monday’s day off.
Josh Reddick hit a solo homer and a two-run single to back Gray (3-0), who retired 13 straight batters during one stretch to help the A’s avoid dropping to five games below .500 for the first time since June 30, 2012. Oakland bounced back against the defending AL West champions after being swept at home over the weekend by first-place Houston.
"We knew that the boys were ready to go today," Lawrie said. "We knew it wasn’t going to stop in the first inning. Even though they did put up a couple, we knew that we had a lot of fight in us. That’s the type of team we are."
Gray allowed two runs and six hits in his 105-pitch day. He lowered his ERA to 1.98 before Evan Scribner struck out the side in order to finish the 2-hour, 6-minute game.
Angels: C Chris Iannetta was held out as a precaution with a cut on a finger of his throwing hand but was expected to play Wednesday night.
Athletics: CF Coco Crisp, recovering from surgery on his right elbow, hit soft toss in the cage and could take regular batting practice Friday before heading out on a rehab assignment with Class-A Stockton this weekend. … INF/OF Ben Zobrist underwent successful arthroscopic surgery on his left knee, performed by Dr. Jon Dickinson in San Francisco. … RHP Jesse Hahn, whose turn in the rotation was skipped as he healed a blister on the tip of the middle finger on his throwing hand, is ready to go Wednesday night.
Angels: Matt Shoemaker (2-1) will be activated from the bereavement list and make his fourth start of the year. RHP Cam Bedrosian is being optioned to Triple-A Salt Lake.
Athletics: Hahn (1-1) pitches for the first time since combining on a seven-hit shutout in a 5-0 win at Kansas City on April 18.