ST. LOUIS — Ten runs in the first inning of their last postseason game for the Cardinals.

No hits Friday night against the Nationals’ Anibal Sanchez through 7²/₃ innings in Washington’s 2-0 NLCS Game 1 win over the Cardinals at a chilly Busch Stadium.

Baseball is the most unpredictable sport.

Sanchez, 35, was terrific, changing speeds, moving the ball to every quadrant, reading swings and leaving nothing over the middle of the plate. The Nats have the big-name starters in Max Scherzer, Stephen Strasburg and Patrick Corbin, but it was the veteran who was magnificent.

The right-hander lost his no-hit bid with a lined single to center with two outs in the eighth by pinch hitter Jose Martinez.

Sanchez then came out of the game, gave a classy wave of his glove to the contingent of Nationals fans along the first base line and was replaced by Sean Doolittle, who got the final four outs for the save.

“From Day 1, Sanchez has been everything we could have asked for and more,’’ Nationals general manager Mike Rizzo told The Post. “His demeanor on the mound has been great, but his clubhouse presence has been immeasurable. It is something you can’t quantify but it is something that is extremely, extremely important for the 2019 Nationals.’’

The Nats signed Sanchez to a two-year deal worth $19 million.

Rizzo said he learned early in his career, “Once you have starting pitching anything is possible, and if you don’t have it, nothing is possible.’’

Sanchez is one of the smartest pitchers in baseball, a game sometimes more worried about velocity than the ability to pitch.

“I just want to be out of the power zone of those guys,’’ Sanchez explained. “I tried to keep the ball on the corners, my two-seamer was working really good and we used it a lot.’’

There have only been two postseason no-hitters. Don Larsen had the perfect game in the 1956 World Series against the Dodgers and the late Roy Halladay for the Phillies in the 2010 NLDS against the Reds.

While with the Tigers in 2013, Sanchez threw six hitless innings in Game 1 of the ALCS against the Red Sox, so he knows about postseason success.

Friday night, Sanchez retired the first 10 batters before he allowed a base-runner, a one-out walk to Kolten Wong in the fourth. Before the game, Scherzer was asked about Sanchez, his teammate in Detroit, and offered this terrific scouting report.

“The biggest thing is that he’s been able to add a cutter,’’ Scherzer said. “The way he can pitch with the cutter to both righties and lefties, that’s the biggest thing he’s added since I played with him. But his ability to change speeds, it’s probably one of the best in the game. The way he can change speeds, even on his changeup, he can change speeds, I mean, he can slow it all the way down, we call it the butterfly, he can throw a butterfly in there and you get guys just every hitter just waves at it.

“So that’s what makes him such a treat to watch, is that I really feel like every pitcher can learn from him because of the way he puts his pitches together and the way he can change speeds.

Float like a butterfly, sting like a bee.

The Nats are riding the hot hand after beating the Dodgers in five games. Anything is possible if you get to the tournament.

The ALCS is about the big guns — Astros vs. Yankees. That is the ALCS America wanted.

Over here in the Wild West NLCS, it has been nothing but surprises and that shows you how wide open the NL is this year.

It also shows the Mets missed a golden opportunity.

As for the Nats, they got the only run they needed in the second when No. 8 hitter Yan Gomes drilled a two-out double to score Howie Kendrick who doubled with one out. For good measure, Kendrick added an insurance run with an RBI single that knocked in Adam Eaton in the seventh.

Noted Gomes, the catcher of Sanchez: “Anytime he was throwing a pitch, it meant something to set up another pitch.’’

The temperature was 41 degrees midway through the game, but the Cardinals hitters were even colder. The magic in the first inning at SunTrust Park that shocked the Braves in Game 5 of the NLDS disappeared because of Sanchez’s brilliant performance.