The two-way star from Japan connected for a long, solo drive in the second inning against Daniel Gossett. The ball landed in the rocks beyond the center-field wall after traveling 136.8 meters. The first player in the majors to attempt to both pitch and hit as a regular since Babe Ruth, the 23-year-old Ohtani had homered in each of his three games between pitching assignments as the Angels' designated hitter.
In Cleveland, Michael Brantley singled home two runs in his first at-bat this season and Carlos Carrasco worked out of a bases-loaded jam in the sixth for the Indians in their chilly home opener.
After a poor performance all around by A's pitchers the night before, it looked like Triggs could have been headed down that same path in the fourth when he surrendered a two-run homer to Justin Upton.
Los Angeles led 6-0.
The Angels trailed 6-0 in the second. Kole Calhoun scored on a wild pitch.
Trout also delivered a run-scoring single in the fourth that extended the Angels lead to 4-0 and drove Graveman (0-2) from the game.
Another followed after he struck out the Athletics' Matt Olson to end the seventh.
Ohtani is the first American League player with a home run and at least two RBIs in each of his first three home games since RBIs became an official statistic in 1920, according to STATS.
Athletics: Oakland put OF Boog Powell on the 10-day DL with a right knee sprain in a move retroactive to Saturday.
Athletics: After a day off in Los Angeles, Sean Manaea (0-1, 1.15 ERA) takes the mound at Dodger Stadium to open a two-game interleague series.
BC-BBA-Athletics-Angels Perfect Game Alert, 1st Ld-Writethru, 260Angels' Ohtani loses perfect game in 7th during home debutAP Photo ANS120, ANS121, ANS119Eds: Updates.
Angels: LHP Andrew Heaney (elbow inflammation) gave up one run and two hits while striking out six in 6 1/3 innings in a rehab assignment at Single-A Inland Empire. Graveman was pulled with just one out in the third as he allowed five runs on five hits with four walks and three strikeouts, throwing only 84 pitches.