LOS ANGELES -- It didn’t take long for Dinelson Lamet to show the Padres what they’d been missing over the past 15 months.

The electric right-hander returned from Tommy John surgery on Thursday night at Dodger Stadium. The fourth pitch he threw was a 98.9-mph fastball, the hardest from a Padres starter all season. The sixth pitch was a filthy, biting slider that Joc Pederson swung over the top of. One batter, one strikeout.

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“It was a really special moment, especially after everything that I went through in the post-op process,” Lamet said through a team interpreter. “It was great to get back out there.”

The rest of Lamet’s night wasn’t quite so smooth. The Dodgers got to him in the fifth when his command faltered and he walked a pair and hit a batter. Lamet finished with three runs allowed on three hits over five innings, as the Padres dropped their series opener, 5-1.

“He worked incredibly hard to be in this position, to be back with us,” Padres manager Andy Green said. “I know the line doesn’t look the way he wants it to look. But just getting him back on the mound, the first step toward being a big part of our staff, is very encouraging.”

Even more encouraging: Lamet struck out seven and showcased the same mouthwatering fastball/slider combo that he used during his breakout 2017 campaign. Heck, it might have been even better. Lamet’s slider took on two different shapes -- a late-breaking high-80s pitch and a low-80s pitch where the bottom dropped out. He sprinkled in about a half-dozen curveballs, too -- an offering he rarely used in ‘17.

Lamet added about 12 pounds during his recovery period, and he’s noticeably bigger. That undoubtedly played into his mid-to-high-90s fastball velocity. Lamet reached 98.9 mph just once in ‘17.

He honed his mechanics, too, in an effort to avoid some of his shortcomings from his rookie season. Lamet posted the highest single-season K/9 in franchise history and was lights-out at times. But he was erratic, too.

“I felt [better] coming up through the Minor Leagues in some of my rehab starts,” Lamet said. “My arm was on time, I'm using my legs, everything's working together. In '17, sometimes it was a bit disconnected, where I'd have a good outing, then a bad outing. So I think [I am better than I was].”

The positives from Lamet’s outing were quickly overshadowed by the Padres’ continued struggles. They dropped their fifth straight game to fall three below .500. The offense was listless against Hyun-Jin Ryu, and Logan Allen coughed up two runs in his first career relief appearance.

The season, which started so promisingly, might be slipping away before the All-Star break -- at least as far as playoff aspirations go.

But in the bigger picture, Thursday offered an unmitigated positive for a pitching staff that had faltered over the past month. One of the Padres’ most exciting young arms is back in the mix.

Fatigue in the fifth

Through four innings, Lamet made one mistake, a middle-in fastball that Max Muncy crushed to the second deck down the right-field line. Otherwise, the Dodgers’ only baserunner reached when a miscommunication between Wil Myers and Fernando Tatis Jr. allowed for a popup to fall in shallow center.

But the fifth inning was different. Matt Beaty opened the frame by lining a 1-2 fastball into center field for a single. Working out of the stretch for just the second time, Lamet walked the next two hitters. He punched out Ryu, but only after running the count to 3-1.

“In those first four innings, I hadn't faced anyone out of the stretch,” Lamet said. “Those first few pitches, I felt like they weren't quite there, and I was leaving my arm behind, dragging. I couldn't quite get to my release point.”

Allen, a lefty starter who is filling a bullpen role for the weekend, got loose quickly in the visiting bullpen. But even with two left-handed batters due up, Green stuck with his starter. The Padres wanted to avoid using Allen in the middle of an inning in his first relief outing, and they’re otherwise thin on lefty options.

Green offered another factor behind his decision to leave Lamet in the game:

“He’s so good, he can pitch himself out of jams better than anyone else can that we have on staff,” Green said. “So you want to give him some leash and latitude to do that, because he’s got wipeout stuff. He showed that through the first four innings.”

Lamet plunked Joc Pederson with the first pitch and surrendered an Alex Verdugo sacrifice fly with the next. The Dodgers led, 3-0, and the Padres wouldn’t threaten from there.

Reyes returns in style

The Padres recalled Gerardo Reyes before Thursday’s game. And when they gave the ball to the rookie right-hander in the seventh inning, they probably weren’t sure which version they’d get.

There’s one version of Reyes with a nasty slider and a high-octane fastball, who is borderline untouchable. There’s another version who can’t find the strike zone and finds himself constantly in hitters’ counts.

The Padres got the untouchable version of Reyes on Thursday. He pitched two scoreless innings with four strikeout victims.

So how do they get that version of Reyes more frequently?

“I just need to attack the strike zone,” Reyes said. “I've learned that not everything needs to be perfect. Just let it go, and I'll be able to have confidence in myself and trust myself.”