SAN DIEGO -- Trouble loomed for the Padres in the sixth inning Tuesday night. You could spot it from a mile away.

Dinelson Lamet had cruised through five no-hit innings, while San Diego grabbed an early two-run lead. But Lamet was about to embark on a third trip through the Dodgers’ lineup -- a relentless lineup stacked with his usual nemeses, patient left-handed hitters.

Even then, Lamet recorded the first two outs in the sixth. But he plunked Justin Turner, and two hits followed, and out of nothing, the Dodgers had tied the game. They would win it, 5-2, with runs in the seventh, eighth and ninth innings against a leaky Padres’ bullpen.

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Once believed to be the team’s strength, the San Diego ‘pen has struggled immensely this season. The Padres entered play ranked 25th out of 30 teams in bullpen ERA, and on Tuesday night that mark crept to 5.89.

Fact is, Jayce Tingler’s most trustworthy bullpen arms haven’t lived up to their billing this year. There’s little the Padres manager can do about that. But Tuesday’s game hinged on two crucial decisions in the middle innings, both of which backfired on Tingler. Let’s take a look at each of them:

Top of the sixth: Corey Seager vs. Dinelson Lamet

The situation: In Tingler’s eyes, Lamet had earned himself some leash with the way he was pitching. He’d lost his no-hitter one batter earlier when Cody Bellinger singled on a soft line drive to center field. But Lamet was otherwise dominant -- and efficient, too, having thrown only 75 pitches to that point.

“He was in cruise control for the most part,” Tingler said. “His pitches were not very high. We were going to go a while with him.”

But the tying runs were aboard, and Lamet has struggled against lefties in the past. Although Seager was 0-for-2, he’d hit two balls sharply, including one that was ticketed for the right-field corner before first baseman Jake Cronenworth made a brilliant leaping grab.

The decision: Tingler had a choice: stick with what got him there, or call for a lefty out of the ‘pen. He stuck with what got him there.

“We had some plans behind it if anything happened,” Tingler said. “But as good as Lamet was, we thought it should be his game to decide at that point in the sixth.”

The result: A grueling nine-pitch battle ensued. On the 84th and final offering of Lamet’s night, he threw a 96 mph fastball right where he wanted it -- at the knees, on the outer half. But Seager went with the pitch and lined a single to left-center field.

“I still felt great in that last at-bat,” Lamet said afterward. “I had everything working still. But it was the third time through the order. I'm a fastball/slider pitcher. Everybody knows that that's my formula. So at the same time, it's the third time through the order, he had seen the movement on my pitches. He was able to put a good swing on a pitch that I executed.”

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To make matters worse, Trent Grisham booted the ball in center field, allowing Bellinger to score from first base, tying the game.

"Lamet was really having his way with us,” said Dodgers manager Dave Roberts. “The Seager at-bat was huge. It was a good pitcher's pitch, Cody going on contact.”

Top of the seventh: AJ Pollock vs. Tim Hill

The situation: Craig Stammen should’ve been out of the inning with the game still tied at 2. He retired two straight Dodgers to start the seventh, then got Austin Barnes to bounce weakly back to the mound. But he airmailed his throw, and Barnes ended up on second base.

That turned the Dodgers’ lineup over once again, sending leadoff man Joc Pederson to the plate with two outs and a man in scoring position. It presented Tingler with another quandary. If he went to a lefty, Roberts would almost certainly counter with a righty pinch-hitter from his bench.

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The decision: Tingler went to that lefty. With Matt Strahm struggling and Drew Pomeranz likely unavailable, having pitched Monday night, it was Tim Hill who got the call.

But the Padres had traded for Hill last month because of his ability to get lefties out. This was a left-on-right matchup in the game’s decisive moment. Tingler was comfortable with that. The Padres had an open base, but opted to let Hill face Pollock with the lefty Max Muncy on deck.

“We had a good idea we were going to make them make a move and flip 'em,” Tingler said. “We had an open base to work with. You've got to pick your poisons with that lineup.”

The result: Another absolute slog of an at-bat. For six pitches, Hill gave Pollock nothing to hit -- sinkers and four-seamers, just off the outside corner. But when Pollock fouled off a tricky 3-2 fastball, he had hung around long enough for Hill to make a mistake.

Sure enough, Hill’s seventh pitch caught too much plate, and Pollock lined it to right field for a go-ahead double. It was a clear lack of execution, given the empty base and the lefty waiting on deck.

"As a hitter, you don't face guys like that too often,” said Pollock. “Same for the umpires. He's a pretty unique pitcher, pretty funky, and I was just trying to get a feel for what the ball was doing. It was moving all over the place. Just trying not to hit it to that Cronenworth guy. Trying to hit the ball back at him up the middle and he beat me a little bit, but it worked out."

“A ball leaked out over the plate, and Pollock hit it to right,” Tingler said. “They've got a lot of good hitters. Hill's been really good for us. He just didn't have it tonight.”

Nor did the Padres, collectively, and their first series against their primary division rivals is tied at a game apiece.