A bunch of big leaguers became marathon men on Saturday.

The Miami Marlins needed 20 innings to outlast the New York Mets 2-1, overlapping for much of the afternoon and early evening with the Toronto Blue Jays’ 4-3 win against the Texas Rangers in 18 innings.

It was the first time two games in the majors on the same day lasted that long since Aug. 15, 2006, when the matchups of Cubs-Astros and Diamondbacks-Rockies each went 18 innings, STATS said.

“It’s neat, man,” said Miami pitcher Kevin Slowey, who earned the win with seven innings of shutout relief. “I tell you what, that’s part of what’s amazing about baseball: There’s always a capacity to come back and tie it up.”

The Marlins and Mets played the longest major league game in more than three years. They threw a combined 561 pitches and took 6 hours, 25 minutes in New York.

“You play 20 innings, you’ve got to win that game,” Miami manager Mike Redmond said.

The Rangers and Blue Jays needed 5 hours, 28 minutes in Toronto. They each equaled the longest game in club history.

Texas played 18 innings for the fifth time in its history, last doing it on June 24, 2004, with a 9-7 win over Seattle.

Toronto had played 18 innings once before, beating the Angels on July 28, 2005. Texas reliever Jason Frasor pitched one inning for the Blue Jays that day — he also worked an inning for the Rangers in this extended affair.

Frasor said these long games are mentally draining for relievers, as well as position players.

“If you’re sitting down in the bullpen, it’s just the anticipation, the preparation, it just exhausts you,” Frasor said. “You’re going, ‘Is this going to be me, is this going to me be?’ and then it’s not you. You just keep waiting and waiting and it’s exhausting.”

Probably the same thing for Rob Brantly of the Marlins and John Buck of the Mets — both catchers played the whole way. Adeiny Hechavarria hit a go-ahead single for Miami in the 20th.

“I’ve got the advantage of youth right now,” the 23-year-old Brantly said. “But 20 innings takes its toll.”

The game began 5½ hours before the Belmont Stakes about 13 miles away — and still ended around an hour after winner Palace Malice crossed the finish line.

The last big league game to last as long also involved the Mets, according to STATS. It came when they beat St. Louis 2-1 in 20 innings on April 17, 2010.

It was the longest game by far in the history of Citi Field, which opened in 2009, and it matched the longest in Marlins history — a 7-6 loss to the Cardinals in 20 innings on April 27, 2003.

“The whole team spirit was up,” said Brantly, who finished with four hits. “We were still having fun in the dugout and still cracking jokes and keeping the energy high. … Still had enough energy to string some hits together and get that run.”

A scattered crowd of 20,338 had dwindled perhaps into the hundreds by the time the stadium sound system played Chuck Berry’s “No Particular Place To Go,” not long after the 14th-inning stretch.

Some of the fans who remained chanted “Let’s Go Home!” as the Mets came to bat in the 17th.

“In a situation like that,” Brantly said, “the team that can keep their enthusiasm up the most usually ends up being the victor.”