LOS ANGELES -- The Padres consider themselves a franchise on the rise in the National League West. They’re loaded with young talent, they’ve got more on the way, and they’ve built a core that should stick together well into the next decade.

But in this division, the bar is high. The Dodgers, on course for a seventh straight division title, offered a stark reminder on Sunday afternoon.

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In a wild series finale, the Padres twice rallied from deficits, only for the Dodgers’ Max Muncy to seal an 11-10 victory with a walk-off two-run double in the ninth. Lights-out closer Kirby Yates and rookie catcher Francisco Mejia had trouble getting on the same page. When they finally did, Yates grooved a fastball that Muncy smacked into right field. Luis Urias’ relay throw home was high, and San Diego fell nine games below .500 for the first time this season.

“We battled,” said first baseman Eric Hosmer, whose third inning grand slam put the Padres on top and was his first since joining the club. “This one's definitely a gut punch.”

For years, the Padres weren’t competitive on their trips to Chavez Ravine. That might be beginning to change. But the results aren't. With Sunday's loss, the Padres finished their season 4-6 at Dodger Stadium, the ninth straight year they've posted a sub-.500 record here.

“We won three of four last time here, and we're basically an out away from splitting here this time,” said Padres manager Andy Green. “We're not that far off. It's a frustrating way to end a series.”

On three fronts, it was a rough day for Padres rookies. Starter Chris Paddack labored from the outset, allowing six runs in four-plus innings. Urias committed a crucial error at second base, allowing the winning run to reach base. Mejia was never quite on the same page as Yates.

All of those struggles proved costly. In the big picture, the Padres hope they prove worthwhile.

“We're putting guys in situations they've never been in,” Green said. “Defending the field in the ninth inning at Dodger Stadium, there's a couple guys on the field that have never done that with a one-run lead before. They're learning. They're growing through that.”

Paddack put it more succinctly.

“Still a lot to learn, man,” he said.

Paddack surrendered second-inning home runs to Muncy and Russell Martin, both on two-strike fastballs when he was ahead in the count. It’s become a worrying trend for the 23-year-old right-hander. Eight of the 17 home runs he has allowed this season have come with two strikes.

Of course, Paddack also entered Sunday with the highest strike rate of any starting pitcher in the Majors, meaning he’s been ahead in a lot of counts. But after the game, he was vocal about his need to change things up with two strikes. He also wondered aloud whether he was tipping his pitches with runners on base -- something he said he will be looking to fix during his next bullpen session.

Despite his struggles, the Padres’ offense picked up Paddack. Manuel Margot launched his fourth homer at Dodger Stadium, the most of any visiting player this season. Hosmer added to his slam with a tiebreaking sacrifice fly in the seventh.

The Dodgers, as they always seem to do, came storming back. Facing a three-run deficit in the eighth, they plated two against hard-throwing Padres rookie Andres Munoz -- the first runs he’s allowed since his mid-July promotion.

In the ninth, Yates surrendered a leadoff double to Joc Pederson, before Hosmer made a brilliant play on a grounder to first, throwing across the diamond to nab Pederson at third.

“It's a shot we like to take,” Hosmer said. “It worked out for us there, trying to be aggressive. Obviously, with Kirby on the mound, if you can get an out like that, you feel pretty confident.”

A batter later, Seager sent a slow chopper toward second base. A game-ending double play seemed unlikely, but perhaps Urias was a bit over-ambitious. If so, it cost him. As he was trying to spin and fire to second, he juggled the ball. He recovered in time for a throw to first, but Seager was safe by a step.

“We trust Luis Urias immensely defensively,” Green said. “He's a very good defender. He's going to make great plays time and time again. That's a tough one.”

Muncy was next, and he worked the count full. In the process, Yates stepped off the mound several times, clearly in disagreement with Mejia. With a 1-0 count, the Padres called a meeting at the mound that lasted nearly a minute.

“When you see their closer taking so much time between pitches and being methodical and calling out the guys to have meetings, for us as hitters: ‘All right, he’s worried,’” said Dodgers outfielder Alex Verdugo, who was on second base at the time. “Doesn’t want to make a mistake.”

Yates downplayed the notion that the inning-long miscommunication was symptomatic of anything larger.

“I think we've been fine,” Yates said of his relationship with Mejia. “Today was just one of those days where he's seeing something different because he's been catching eight innings, and I've got a certain way that I like to pitch. ... Bottom line is I didn't execute my pitches. That's the only thing that mattered.”

After Muncy’s double, Yates raced behind home plate to back up the throw. When Seager slid home safely, Yates unleashed a yell in the direction of both Mejia and home-plate umpire Jerry Meals (who hadn’t given Yates much benefit of the doubt). Yates insisted there wasn’t anything to read into his reaction.

“It was frustration,” Yates said. “Over everything. I expect myself to get out of that. It's not fun getting walked off on on the road.”