PHILADELPHIA — The first stage of what the Mets hope will be a great October champagne chug-fest tentatively is set for Friday night at Citizens Bank Park.

Every other bounce has gone in the Mets’ direction over the past six weeks, so why wouldn’t they clinch a National League wild-card berth sooner rather than later and eliminate the stress of needing a Sunday victory or — heaven forbid — a tiebreaker scenario?

This much was clear as the Mets enjoyed their day off on Thursday: The Cardinals were in trouble in the race and the Giants’ chances of overtaking the Mets for the top seed, which carries the home field for Wednesday’s wild-card game, were fading.

But the Cardinals and Giants both got wins.

San Francisco beat the Rockies, 7-2, leaving them a game behind the Mets and one game ahead of St. Louis, which got a controversial 4-3, walk-off win over the Reds.

The Cardinals are two games behind the Mets, meaning a Mets win and a Cardinals loss on Friday would lock up a wild-card spot for the Amazin’s.

A wild card may not have been the goal for these defending NL East champions when the season began, but given the number of players lost to injury this summer — particularly in what has become a makeshift starting rotation — the Mets gladly will take any port of entry. The only consecutive postseason berths in franchise history were in 1999 and 2000.

Few could have imagined the Mets being in this position following their loss at San Francisco on Aug. 19 that knocked them two games below .500. Since then the Mets have gone 25-12 — minus Steven Matz and largely without Jacob deGrom. Both stud pitchers have been shut down because of arm ailments, placing the burden on rookies Seth Lugo and Robert Gsellman, neither of whom figured into the team’s plans when the season began. Both have responded, pitching to a 2.74 ERA in 14 combined starts, helping save the Mets’ season from ruin.

Meanwhile, Yoenis Cespedes, Asdrubal Cabrera and surprising rookie T.J. Rivera have helped carry the lineup. But the biggest recent offensive threat has been Curtis Granderson, better late than never. In September, the veteran outfielder has eight homers and 21 RBIs in 24 games, reverting to last year’s form, when he was the team MVP.

“After I moved him to the fourth hole, it’s a whole different animal,” manager Terry Collins said. “This guy is getting walks, he is getting big hits, hitting home runs — he’s played great for us. Especially when we all turn to Cespedes to carry the load, and the nights he’s had a rough night you look up and it seems like Curtis has had a good night. That is what you are supposed to do. You are supposed to pick each other up here.”

The Mets won two of three games against the Phillies last weekend at Citi Field, including a 17-0 demolition of Philadelphia in the finale.

Then, amid the heartbreak of Jose Fernandez’s death in a boating accident, the Mets won two of three games in Miami.

Ideally, the Mets would like to clinch the wild-card berth and home-field by Saturday night, rendering Sunday’s game meaningless and putting ace Noah Syndergaard in position to start the wild-card game on Wednesday. Collins has said he is unsure if he would pitch Syndergaard if the wild-card berth is clinched, but home-field unresolved.

“We can’t worry about what anybody else is doing — it’s just play baseball,” Jay Bruce said. “We’ve been doing a good job of it.”