Johan Santana was past 130 pitches and fans at Citi Field were high-fiving with every out, hoping this was finally the night the New York Mets had waited for.

All those famous arms — Nolan Ryan, Tom Seaver, Dwight Gooden, Pedro Martinez, Tom Glavine — and not a single no-hitter in more than 50 years of baseball.

Not until Santana finished the job Friday night.

The two-time Cy Young Award winner pitched the first no-hitter in team history, aided by an umpire’s mistake and an outstanding catch during an 8-0 victory over the St. Louis Cardinals.

After a string of close calls over the last five decades, Santana went all the way in the Mets’ 8,020th game.

“Finally, the first one,’’ he said. “That is the greatest feeling ever.’’

He needed a couple of key assists to pull it off.

Carlos Beltran, back at Citi Field for the first time since the Mets traded him last July, hit a line drive over third base in the sixth inning that hit the foul line and should have been called fair. But third base umpire Adrian Johnson ruled it foul and the no-hitter was intact — even though a replay clearly showed a mark where the ball landed on the chalk line.

“I saw the ball hitting outside the line, just foul,’’ Johnson told a pool reporter.

The umpire acknowledged that he saw the replay afterward, but declined to comment.

“It was in front of his face, and he called it foul. I thought it was a fair ball,’’ Beltran said. “At the end of the day, one hit wasn’t going to make a difference in the ballgame.’’

With the next batter at the plate, though, Cardinals third base coach Jose Oquendo twice got in Johnson’s face for heated arguments — the two even appeared to bump each other. Rookie manager Mike Matheny also came out to protest, but nobody was ejected.

“It’s not like there’s going to be an asterisk by it. That’s the way the game goes,’’ Matheny said.