As much as Marlins manager Don Mattingly preaches about staying in the moment, he did let on that this marathon seven-game series with the Phillies matters.

“We’re basically going to play a World Series in five days,” Mattingly acknowledged pregame on Thursday afternoon.

The Marlins have plenty of unfinished business to make the playoffs, but in the series opener, they got their first taste of a walk-off celebration. Jorge Alfaro’s two-out RBI single in the ninth inning lifted the Marlins to a dramatic 7-6 victory at Marlins Park.

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Formerly with the Phillies, Alfaro delivered with two runners in scoring position. According to Statcast, the single up the middle had an exit velocity of 107 mph.

“It's not a secret, we have a lot of young guys with a lot of talent,” Alfaro said. “We never get down. We're always going to be fighting for every game. Right now, we're playing like a family. You can see in the clubhouse, and in the dugout, everywhere. We're going to be fighting. No matter what. No matter the score.”

The Marlins rallied for three in the eighth inning before walking it off in the ninth a night after taking the organization’s most lopsided loss in history -- 29-9 to the Braves.

Now 20-19, the Marlins moved to within one-half game back of the second-place Phillies (21-19) in the National League East.

Miami’s resiliency is not a surprise to Mattingly. The club overcame a COVID-19 outbreak the first weekend of the season, which halted its season for days. The Marlins have made more than 130 roster moves, and they still find themselves in the playoff picture.

“We've been through a lot,” Mattingly said. “Any time it looks like we're going to fade, they kind of show up and put a W on the board and keep it going. I didn't have any doubt about our guys today. Getting in late [around 3 a.m. ET], we didn't do a whole lot on the field, but I knew these guys would be ready to play.”

In the ninth inning, Brian Anderson got things going with a single off Brandon Workman, and he was lifted for pinch-runner Monte Harrison, who advanced to second on a groundout. Harrison then stole third, showing aggressiveness with All-Star J.T. Realmuto behind the plate. After Jazz Chisholm struck out with two runners in scoring position, Alfaro sent the Marlins into a socially distanced walk-off celebration.

Harrison’s ability to get to third was a big play.

“Obviously, that changes things,” Mattingly said. “Then at that point it's like a leadoff double, and the guy bunts him over. It puts them in a spot. Do they walk people? What do they want to do? Then it sets up what happens at the end.”

Alfaro, of course, was acquired by the Marlins from the Phillies as part of the Realmuto trade.

His heroics capped the comeback. But the momentum started in the eighth, when Miami loaded the bases off Tommy Hunter. Workman inherited the jam, and Starling Marte went to the opposite field with a three-run double off the wall.

Acquired from the D-backs at the Aug. 31 Trade Deadline, Marte sees a youthful Miami squad coming together.

“The unity,” Marte said via an interpreter. “It's something I've seen with this team. It drives me to go out there and give my 100 percent, and things are working out well.”