Darvish pitched 5.2 innings with 7 strikeouts; Tatis Jr. delivers a walk-off hit in extra innings to win the game.

Jackson Merrill’s towering fly ball into the right-center gap at Petco Park stayed airborne for roughly five seconds. It seemed to last forever.

The whole Petco Park collectively held its breath. With two outs and two runners dashing on the bases, Merrill was running as well. At last, after that fleeting moment of suspense, the ball hit the ground. Reds outfielder TJ Friedl made a desperate dive, but the ball bounced off his glove.

The stadium erupted. Both runners scored. Merrill sprinted to third base and flexed his muscles. It was only the sixth inning. But after rallying from a three-run deficit, the Padres had momentum with a well-rested bullpen and a passionate crowd behind them.

Merrill said after the game, “We were always going to win this one.”

A few innings later, the Padres did just that. Ultimately, it was Fernando Tatis Jr.’s walk-off sacrifice fly that sealed the dramatic and crucial 4-3 victory — marking Tatis’s fourth career walk-off RBI and his second this season.

In the process, the Padres stayed tied with the Dodgers in the National League West race, remaining just one game behind after Los Angeles’s win. Meanwhile, with both the Cubs and Mets losing Monday night, San Diego closed the gap in the wild card chase.

“It’s incredible,” said designated hitter Gavin Sheets, who reached base four times. “Every game matters so much. The fans know it, the teams know it. Obviously, the Reds are in the hunt too. This is what makes September baseball so exciting. Being back here and part of it is exactly why I wanted to be here.”

Tatis sparked the comeback in the sixth inning with a single and a stolen base, then scored on Sheets’s 25th double of the season (a career high). After two more hitters, Merrill’s triple tied the game — and then the Padres put their winning formula into motion.

Their dominant bullpen locked down the victory, with six relievers combining for 4.1 scoreless innings. Then, in the 10th inning, Freddy Fermin’s perfect sacrifice bunt led to a throwing error, allowing Tatis to deliver a deep fly ball for the walk-off hit. When Jake Cronenworth touched home plate, Tatis was surrounded by teammates near first base, and his jersey was torn off within seconds.

“We just kept moving forward,” said manager Mike Shildt. “That’s what this team is about… Freddy’s bunt, Tatis’s smart, tactical hit — no frills. It was a really good baseball game.”

It was also an important win. Of course, the Padres’ main focus is winning the NL West. But if they secure the top wild card spot, they gain almost the same advantage as winning the division: hosting the wild card series at Petco Park. In that regard, they trail the Cubs by just two games.

At the same time, they are closing in on clinching a playoff berth. Defeating the Reds, one of the teams on the playoff bubble, was significant. But perhaps most importantly, the Padres have won three straight games and are starting to play their style again — unlike the team that lost nine of eleven previously.

“We went through a tough stretch,” Sheets said. “We needed to get out of it quickly. The hitters are coming around, the pitching is strong. I feel like we’re playing complete baseball.”

The game didn’t start well: Darvish gave up a leadoff home run to TJ Friedl after a PitchCom-related miscommunication. Immediately after, Darvish and catcher Freddy Fermin had a heated discussion on the mound.

Apparently, Darvish intended to call a two-seam fastball, but for some unknown reason, the signal didn’t reach Fermin’s device. Meanwhile, Fermin called for a curveball. With the pitch timer about to expire, Darvish didn’t want to mismatch signals with the catcher, so he threw the curveball — and Friedl promptly sent it out of the park.

Darvish was affected — yet he ultimately pitched better than his final line (5.2 innings, 3 runs) suggested. The Padres’ bullpen behind him performed excellently.

Jeremiah Estrada and Adrian Morejon took over in the seventh. Mason Miller was dominant as usual in the eighth. Robert Suarez was efficient enough in the ninth to return for the 10th inning. Before boldly bringing in lefty Wandy Peralta to face left-handed hitter Friedl, Suarez retired all five batters he faced. Peralta induced a harmless fly ball to left field from Friedl, setting the stage for Tatis.