SAN DIEGO -- Charlie Morton’s fond memories of pitching in Petco Park couldn’t prevent a forgettable performance on Thursday.

Morton struggled and the Atlanta Braves again staggered as they fell to the Padres, 12-1, to open their first road trip as the defending world champions.

After a lackluster homestand to begin the season, in which the Braves dropped four of seven games, they looked scratchy in America’s Finest City.

Atlanta’s pitching wasn’t sharp, its fielding far from crisp (three errors) and its offense -- which has scuffled in all but two games -- was ineffective.

“We shot ourselves in the foot with the errors we made that we normally don’t have and letting them run around the bases,’’ Braves manager Brian Snitker said. “We’ve got to do a better job of what we can control.’’

That Morton, who was solid in winning in his season debut, was wobbly against the Padres was likely the biggest surprise.

“They seemed to be all over the heater,’’ said Morton, who notched his 1,500th career strikeout when fanning Wil Myers in the third inning. “They laid off some breaking balls that were pretty good. They were just below the zone or just outside. They waited it out for their pitches.’’

Morton had dominated San Diego in winning six of his seven career decisions, pitching to a 2.09 ERA in nine starts. Included in that run was keeping San Diego scoreless over his past 16 2/3 innings.

The right-hander’s previous start at Petco Park saw him throw 5 2/3 shutout innings in Game 7 of the 2020 American League Championship Series, in helping the Rays advance to the World Series.

But all those good vibes dissipated quickly before a sellout crowd celebrating the Padres’ home opener had barely settled in.

About the only thing the Braves could toast was that Morton (1-1), despite his early hiccups, lasted five innings to save the bullpen.

“I like the fact that he regrouped and went five innings and got his pitch count up,’’ Snitker said. “That was big for us and for him.’’

Morton should be commended for that as his line reveals just how challenging his outing was: five runs, nine hits, three walks and two hit batters, with five strikeouts.

“My mix (of pitches) wasn’t there early enough,’’ Morton said. “Then it just became a grind.’’

While Morton was rocky, the Padres’ Joe Musgrove (1-0) was on a roll. He allowed only one Brave to reach third base in his 6 2/3 innings of work as he snapped the Braves’ six-game winning streak at Petco Park.

“He was really good tonight,’’ Snitker said. “He’s tough. He’s a very competitive guy and when he’s got his breaking stuff working, he is a rough ride.’’

Atlanta managed just four hits against Musgrove, two coming from Matt Olson.

It didn’t fare much better against three Padres relievers -- although Ozzie Albies had a solo homer in the ninth – as the Braves have scored more than three runs just once in their first eight games.

“We are not swinging the bats great right now,’’ Snitker said. “We got a couple of guys swinging it OK, but we’re having a tough time keeping the line moving and bunching anything together. It’s magnified, I think, when it's in the beginning. You just gotta keep fighting through it.’’

The heart of the Braves’ order offered little resistance. Austin Riley, Marcell Ozuna, Travis d’Arnaud and Eddie Rosario were a combined 1-for-15.

Atlanta fell behind 5-0 in the second inning when Luke Voit’s double brought home Manny Machado, who was aboard on the first of his five hits, with one being a two-run homer in the seventh.

Rookie shortstop C.J. Abrams, who’s getting a chance with All-Star Fernando Tatis Jr. (wrist) sidelined, went the opposite way for his first career homer as he just cleared the left-field wall before Voit’s extra-base hit.

Morton labored in the first inning, as he struggled with his command in hitting two of the first four Padres he faced.

Still, Morton nearly wiggled from the early two-out, bases-loaded jam. But Eric Hosmer parachuted a two-run single into short center field and Myers’ followed with an RBI single for a 3-0 Padres lead, and the Braves never mounted a comeback.