SAN DIEGO -- The Padres christened Petco Park with a comeback victory in 2004. Twenty years later to the day, they matched the biggest comeback victory in franchise history.

After spotting the Cubs eight runs on Monday night, the Padres stormed back for a 9-8 victory in the series opener. The Padres scored seven times in the sixth inning and then won it on Fernando Tatis Jr.’s two-run home run in the eighth.

With the Padres down a run and Jackson Merrill on first base, Tatis stepped in against right-hander Adbert Alzolay and promptly got spun by a fastball inside. Undeterred, he ripped a slider 100.4 mph off the bat and into the left-field seats.

Tatis held his bat triumphantly above his head, then flung it away as he took his initial steps toward first base. One more pause for a celebratory fist pump, and Tatis broke into his trot, wearing custom cleats adorned with Tony Gwynn’s No. 19 in honor of the Petco Park anniversary.

“Definitely the shoes,” Tatis said. “The power came from above. Always grateful and definitely a little bit inspired.”

Tatis’ shoes were not a matched pair. One was in the colors of the Padres’ 1984 World Series squad, the other in the colors of their 1998 World Series team.

Gwynn never played at Petco Park, but he was part of that ’98 club that rallied support for the construction project. And he was a regular for years in the Padres’ new home, either part of the broadcast team or watching his son, Tony Gwynn Jr., play.

Not even Gwynn participated in a game quite like this.

Three times before -- but only once at Petco Park -- the Padres had come from eight runs down to win a game:

• July 8, 2021: vs. Washington, 9-8
• June 10, 1974: vs. Pittsburgh, 9-8
• May 23, 1970: at San Francisco, 17-16 in 15 innings

“I couldn’t be more pleased,” Padres manager Mike Shildt said. “It’s not an easy thing to do. We could have easily checked out. … When that score was 8-0, they actually came together more, started talking more and started saying, ‘OK, how are we going to figure this thing out?’

“Really impressive. I’m proud of the club.”

The turnaround Monday was stunning in its swiftness and relentlessness. Cubs starter Javier Assad was working on a two-hit shutout entering the sixth. Then Tatis drew a walk to start things and Jake Cronenworth got the Padres on the board with his first home run of 2024. Assad (104 pitches) was lifted, and the Padres jumped on the Cubs’ bullpen.

In all, the Cubs used three pitchers in the half-inning, and the Padres sent 10 batters to the plate while collecting five hits and two walks. Ha-Seong Kim had a two-run triple, and Luis Campusano brought him home on a groundout. Xander Bogaerts capped the rally by matching Cronenworth -- a two-run homer, his first of the year.

Cronenworth didn’t just put the Padres on the board. His nine-pitch battle with Assad helped further drive up the pitch count and showed his teammates that he was all-in on every pitch. Cronenworth lined the first pitch deep toward right field, but foul. It’s rare that a hitter gets the homer in the same at-bat as a near-miss -- Cronenworth said he never had -- but a second opportunity came on a full-count cutter.

“Turning point,” Shildt called it.

Said Cronenworth: “It’s something we’ve been talking about all year -- not taking any at-bats off. … It seems like guys just kept grinding and having good at-bats all night.”

Tatis later ensured that the Padres’ comeback wouldn’t fall excruciatingly short. He addressed the postgame crowd at his locker barefoot, begging a question: What happens to the shoes now?

“I’m going to just keep playing with them,” Tatis said. “Hopefully, they keep sending that good luck. I’m just happy I was wearing those shoes today.”