By Jessica Kwong

AP photo: Oakland A’s Danny Valencia singles off Los Angeles Angels pitcher Jared Weaver in the fifth inning at Angels Stadium on Monday night

 ANAHEIM–Despite an impressive start on the mound by rookie left-hand pitcher Sean Manaea, the Oakland Athletics fell 2-1 on Monday night in the first of a three-game series at Angel Stadium.

 The loss is latest in a string of slow starts for the A’s, at a season-high 22 games under .500 for the third time this year.

 “You’d think we’d do a little bit more damage early on, we just didn’t,” A’s manager Bob Melvin said. “We go through these spurts where we have a seven-run inning and we don’t do much after that, we have four or five games where we swing the bat great and three or four games where we don’t.”

 The Los Angeles Angels of Anaheim took a 1-0 lead in the fourth inning, when Mike Trout hit a home run his 29th of the year on a fly ball to left center field.

 Manaea admitted, “I don’t know what to do against (Trout).”

 “It just seems like he has my number. He seems like he knows what to do off me and he did it again today,” said Manaea, adding that otherwise, “Everything felt really good today and I would say it was one of the better starts.”

 The A’s evened the score at 1-1 when Stephen Vogt hit a home run on a line drive to right field in the sixth inning.

 In seven innings, Manaea scattered four hits and struck out three against one walk.

 “He’s everything that we want him to be aside from maybe a few outings early on, where he was just kind of getting his feet wet,” Melvin said of Manaea. “He’s been brutal and dominate at times, even against good lineups.”

 But in the eight inning, the Angels’ Albert Pujols grounded out softly with pitcher Ryan Dull throwing to first baseman Yonder Alonso and Yunel Escobar scored to put the Angels back up 2-1.

 “I was going too fast because I knew I wanted to do anything possible to get the guy at home,” Dull said. “It’s really frustrating, because you know you executed the pitch you wanted, it just didn’t go to the exact spot you wanted it to.”

 The A’s couldn’t get score any runs after.

 Angels starting pitcher Jered Wever left the game after the fifth inning and 71 pitches due to tightness in his lower back.

 The A’s, at 67-89 and 2 1/2 fames behind the Angels, are at the bottom of the American League West.

 First pitch for game two of the series is 7:05 p.m. Tuesday the A’s will start Daniel Mengden 2-8 against the Angels Ricky Nolasco 7-14 at the Big A