LOS ANGELES — Dodger Stadium itself is coming to realize what opposing pitchers already know about Shohei Ohtani.

The old cathedral on the hill is struggling to contain Ohtani’s power and not just when it comes to the wall just beyond the outfield grass.

Ohtani crushed a leadoff home run in a seven-run first inning that nearly left the ballpark entirely as the Dodgers ultimately held on for a 8-7 victory over the Colorado Rockies on Wednesday and the third three-game home sweep already this season.

Ohtani’s 448-foot blast landed in the back row of the right-field pavilion and just shy of the zig-zag corrugated metal roof. His 473-foot home run to right-center last season against the Boston Red Sox missed landing on the roof by inches.

Wednesday’s drive merely lit the fuse for a huge first inning when the Dodgers sent 12 batters to the plate. Freddie Freeman hit a home run in the inning, while Andy Pages had a two-run single, and Austin Barnes delivered a two-run double.

Ohtani’s second at-bat of the inning ended in an RBI single.

The early offense helped cover a shaky season debut from right-hander Bobby Miller, who gave up a third-inning grand slam to UCLA alum Michael Toglia. Former Angel Mickey Moniak followed with his own home run as the Rockies erased nearly all of the Dodgers’ early six-run lead.

Miller did offer hints of his promise with seven strikeouts among his first eight outs, but his three outings at Triple-A were a mixed bag too with 11 strikeouts and 11 walks in 12 innings.

Miller’s path over the last year has been far from smooth with a shoulder injury last April, a demotion last July and a line drive off the side of his head during his first outing this spring. Through it all, the Dodgers continue to think the ceiling for the 26-year-old remains high.

“Obviously, with things that have happened, he’s had to work his way back,” manager Dave Roberts said. “But as far as the upside potential, oh, absolutely (it’s high).”

The Dodgers added a run in the fifth inning on a Pages single, with the bullpen holding the Rockies to a single run the rest of the way.

Ben Casparius (1-0) recovered from a brutal outing Saturday against the Chicago Cubs, when he allowed six runs in 1 2/3 innings, to give up one run over three innings Wednesday.

Tanner Scott pitched the ninth inning for his sixth save, while Max Muncy had two hits for just his second multi-hit game of the season.