SAN DIEGO -- The sky wasn’t really falling, unless one counts the moisture from earlier in the day, as the Padres opened a seven-game homestand against the Brewers on Thursday night at Petco Park.

That San Diego christened the three-game series with a 4-3, 10th-inning loss only exaggerated the angst of Padres fans.

How the expectations for the Friars have changed.

It seemed unlikely that the Padres would make a game out of it after a mostly tepid offensive performance. Then center fielder Trent Grisham stepped to the plate in the eighth inning.

Grisham hit a two-out, two-run homer off former San Diego No. 1 overall Draft pick Matt Bush to bring the Padres even, 3-3.

Ex-Brewer Josh Hader breezed through the ninth inning, much like he dominated in his five-and-a-half seasons in Milwaukee.

But Luis García allowed an unearned run on a sacrifice fly from Rowdy Tellez in the 10th after a double steal, and with San Diego unable to produce more late magic in the bottom of the inning, that was that.

The Padres' chances for another rally were derailed when automatic runner Brandon Dixon was thrown out at third base when trying to advance on a ball hit to shortstop Willy Adames.

“Your instincts are that if a ball is hit behind you softly, you go to third,’’ Dixon said. “But he made a good play.’’

That put San Diego on the wrong end of another close game.

“Tough loss,’’ Padres manager Bob Melvin said. “I mean, we got the momentum on our side with the homer, we got Josh coming into the game and the middle of our order up. So it felt like we were in a pretty good position, but obviously, it didn’t work out.’’

Not long ago, coming off a 4-3 road trip against the powerful Braves and Mets was celebrated in San Diego. But there was also some hemming and hawing from the locals over their star-laden team dropping two of three to New York in the runup to playing Milwaukee.

That’s the cost of doing business with a Padres payroll that ranks No. 3 in MLB. Still, the calendar reads mid-April, and the Friars should right themselves soon.

But all that will likely happen in the future. The present is no gift, with San Diego having won just as many games (seven) as it has lost.

“We just haven’t hit our stride yet,’’ Melvin said. “We’re a better team than that.’’

It’s a club that should get better soon when Fernando Tatis Jr., who had three home runs for Triple-A El Paso on Thursday, reaches the end of his suspension for PED usage.

“It’s not a surprise,’’ Melvin said. “He’s ramping up.’’

Soon after the San Diego State men’s basketball team, which played in the NCAA title game, was honored before first pitch, Tellez sent right-hander Nick Martinez’s curveball over the right-field fence for a two-run blast.

It took third baseman Manny Machado until the Padres’ 14th game to hit his first homer. His full-count blast off right-hander Colin Rea’s 94-mph four-seam fastball landed in the right-center field seats to slice the Brewers’ lead to 2-1 in the first inning.

Milwaukee flexed its muscles again in the fifth inning when third baseman Mike Brosseau crushed Martinez’s flat sinker to dead center for a 3-1 cushion.

San Diego, meanwhile, was befuddled by Rea, and they weren’t the only ones unfamiliar with his arsenal. The right-hander, who wasn’t named the starter until hours before the game, last pitched in the big leagues in October 2021, and he had never faced the Padres.

Rea spent last season in Japan, where he went 5-6 in a swing role that leaned toward him starting. But he had more than enough to keep the Friars’ bats at bay on Thursday.

Relying on a four-seam fastball and an array of cutters, sliders and sinkers, Rea was nearly untouchable. It’s one thing to get stymied by the Mets’ Max Scherzer, as was the case in Monday’s loss in New York.

Few saw this coming from Rea, who broke into the Majors with San Diego and made 25 appearances for the Padres from 2015-16.

Despite his anonymity, Rea was brilliant, and his line proved it: 5 2/3 innings, one run, two hits and six strikeouts. He retired the final 10 batters he faced.

After shortstop Xander Bogaerts singled in the first, the Padres didn’t get another hit until after Rea was relieved. They finally made some noise off righty Peter Strzelecki in the seventh inning, when Bogaerts and Nelson Cruz produced one-out singles.

Then Jake Cronenworth came to the plate with the crowd revved. He bounced into an easy double play, and some of those boosters that arrived in a sour mood headed for the exits.

They missed a whale of a rally, even if it fell short.