Starter Gio Gonzalez is relegated to supporting actor Tuesday in St. Louis, but he keep the Nats in the game by allowing two innings over seven effective innings and 110 pitches. (Dilip Vishwanat/Getty Images)

Baseball does not always need meaning to matter. In the ninth inning, Ryan Zimmerman stood on deck as Busch Stadium came alive. The crowd roared for Michael Wacha, the 22-year-old St. Louis Cardinals rookie right-hander. As Zimmerman walked to the plate, the Washington Nationals’ irrelevance in the standings faded away. “That was like a big-time playoff atmosphere,” Zimmerman said later.

One night after the Nationals’ hopes met mathematical elimination, Zimmerman had found something unexpected to play for: not being the last victim of Wacha’s no-hitter. Wacha pitched a no-hitter for 26 outs. He came within one out — within one inch twice on the play — from throwing a no-hitter against them in the Nationals’ 2-0 defeat.

The Nationals avoided being no-hit for the first time since baseball returned to Washington only on the most heart-wrenching of hits, on Zimmerman’s chopper over the mound and off Wacha’s glove. Shortstop Pete Kozma, a villain forever in Washington because of his postseason heroics last year, barehanded the ball and fired on the run. His throw pulled Matt Adams off first base, and Zimmerman snuck behind his sweep tag by a few inches.

“That’s baseball,” Zimmerman said. “Baseball is weird. We hit balls on the screws all night, and that’s the swing, that’s the hit that breaks it up.”

As the crowd groaned, Cardinals Manager Mike Matheny came out to shake Wacha’s hand and take the ball. The what-ifs rippling through the crowd turned to cheers as Wacha walked off the mound. He had allowed two walks and just the one hit while striking out nine in 82 / 3 nonpareil innings.

The Post Sports Live crew tries to pick a reason why the Nationals did not live up to the offseason expectations. (Post Sports Live/The Washington Post)

“That Aggie pitched a heck of a ballgame,” said Manager Davey Johnson, a fellow Texas A&M alum.

As Zimmerman stood on first base, Jayson Werth walked to the plate as the tying run. Gio Gonzalez had been reduced to a supporting actor, but he also kept the Nationals in the game, allowing two runs over seven innings. When Werth grounded to first, the crowd started roaring again, for Wacha and what almost happened.

In the 2012 draft, high school sensation Lucas Giolito dropped because of injury concerns, and the Nationals took him with the 16th overall pick. If Giolito had not fallen to them, the Nationals may well have drafted a skinny, 6-foot-6 right-hander from Texas A&M named Michael Wacha. The Cardinals took him three picks later, 19th overall, the draft choice they gained as compensation for Albert Pujols leaving in free agency.

Wacha tore through the Cardinals’ minor league system and became a key figure in their season. He made his ninth major league start Tuesday night. In his first 14 appearances, six of which came in relief, Wacha had punched up a 3.21 ERA. He struck out a batter per inning, and the league hit .234 against him.

The Cardinals handed him the ball Tuesday in trying to close out the NL Central. The Nationals had not been so thoroughly dominated all year. Wacha retired the first 14 hitters he faced and struck out seven of them. The Nationals were late on his mid-90s fastball, which reached 97 mph. And they were fooled by his change-up, which hummed into the high 80s and burrowed into the dirt at the last moment.

Wacha lost his bid for a perfect game when Adam LaRoche rolled a groundball to second base with two outs in the fifth. A coach could not have hit a truer grounder with a Fungo bat. But the ball rolled through Matt Carpenter’s legs, and LaRoche became the Nationals’ first base runner.

Wilson Ramos ended the fifth with a liner to right field, which began a string of near-misses. Anthony Rendon led off the sixth inning with a bullet to short, right into the glove of shortstop Kozma. Gonzalez ripped a line drive to left, but it also found leather rather than turf.

“You were hoping it would drop,” Gonzalez said. “He was catching a lot of breaks. There were guys making some good plays. At the same time, he pitched great.”

With two outs, Denard Span dropped a bunt attempt down the third base line. As the ball trickled foul across the chalk, the crowd hurled boos at Span. With the element of surprise no longer at his disposal, Span swung away. He chopped to second to end the inning. After six innings, Wacha had thrown 54 out of 70 pitches for strikes.

Wacha needed only nine outs. Zimmerman moved ahead, 2-0, and then Wacha threw him four consecutive change-ups. After one strike, Zimmerman looked back at the home plate umpire — catcher Yadier Molina’s framing had earned a call. Zimmerman drew a walk, but the surprising pitch selection revealed Molina’s crucial role in Wacha’s gem.

“Yadi does such a good job of receiving the ball that he gets a lot of calls that other guys don’t get and rightfully so,” Zimmerman said. “Yadi is one of the best, if not the best, back there calling games and things like that. But to throw four or five change-ups in a row when you throw 94-97, that’s not something I expected. And he was throwing it for a strike, too.”

Wacha immediately returned to dominance. Werth popped up to right. Bryce Harper waved at a change-up that bounced in front of the plate for strike three. Ian Desmond whacked a grounder to second.

Six outs to go. LaRoche checked his swing on a 3-2 change-up and drew a leadoff walk. Ramos grounded the 2-0 fastball on three hops to Kozma, who started a 6-4-3 double play. Rendon drew gasps when he poked a flyball to the left field corner, but Shane Robinson made a long run and tracked it down a few feet from the side wall.

“We’re trying to win that ballgame,” LaRoche said. “And then you get in the ninth inning and then it’s just, ‘Let’s get a hit and not be on the highlights for the next 10 years.’ ”

Three outs to go. No one in the majors had more pinch hits than Steve Lombardozzi’s 13. He moved ahead, 2-0, in the count, but grounded a 2-1 fastball to Kozma, who handled it on a backhand.

Two outs to go. Up came Span. No bunts this time. Wacha nodded when Yadier Molina called for a 3-2 change-up. He painted the outside edge. Span started his swing but could only watch strike three.

“Pretty much exemplifies his thought process at the time,” Matheny said. “He was able to tune everything out.”

One out to go. Zimmerman so rarely swings at the first pitch, but he decided he would look fastball. “The change-up was so good, I didn’t want to get to that,” Zimmerman said.

Wacha fired a 97-mph fastball. Zimmerman swore it looked like a cutter, but he swung anyway and made weak contact. The ball grazed Wacha’s glove. Kozma charged and fired from the middle of the diamond. Zimmerman charged down the line.

“I was just using my blazing speed,” Zimmerman said. “Trying to get there as fast as I can.”

He have beaten the throw, anyway, but Adams had no chance to tag him. The official scorer called it a hit. On first base, Zimmerman asked Adams, “Did Pete barehand it?” He would walk off the field a moment later, another loss the Cardinals, but at least not a no-hitter.