All summer long, one massive series kept looming on the schedule.

Three games between the Mets and Braves in Atlanta during the final week of the season. With the NL East rivals locked in a heated wild-card race, surely it would come down to their head-to-head matchup.

And here we are.

“We knew it a couple of weeks ago: That series was probably going to help decide this thing. We know what we’re up against and we know what we have to do,” Atlanta catcher Sean Murphy said. “It just comes down to us. If we win, we’re in.”

Indeed, if the banged-up Braves are going to earn a seventh straight playoff berth, they’ll need a big performance at home.

And if the surprising Mets are going to finish this postseason push, they can do it by toppling a familiar nemesis.

On the line at Truist Park, nothing less than legacies — and a chance to play in October.

“I’m stoked for the opportunity,” said New York slugger Pete Alonso, set to become a free agent after the World Series.

With six regular-season games remaining, both teams were off Monday heading into their series opener tonight. New York (87-69) was tied with Arizona for the second of three National League wild cards, while the Braves (85-71) were two games back.

The teams have split 10 meetings this year, so the winner of their three-game set holds the season-series tiebreaker if the Mets and Braves finish with the same record.

New York knows two wins in Atlanta would clinch a playoff spot. But a sweep by the Braves puts them in the driver’s seat going into the last weekend of the season.

Phillies clinch NL East title >> Kyle Schwarber and J.T. Realmuto homered and Aaron Nola struck out seven to help the Philadelphia Phillies clinch their first NL East title since 2011 with a 6-2 win over the Chicago Cubs on Monday night in Philadelphia.

Carlos Estévez retired Michael Busch on a flyball to end it, and the Phillies swarmed each other in excitement on the infield. The Phillie Phanatic stormed the celebration waving a 2024 flag as fans stood and filmed it all.

With a postseason berth already clinched last week, the Phillies won their 12th division championship — and have their sights set on the No. 1 seed in the National League playoffs.

Philadelphia won five straight NL East titles from 2007-11, then went 10 years without making the playoffs.