The decisive moment of Argentina’s penultimate step toward a Copa América repeat was just like the rest of the climb: simple.

It wasn’t easy. The Argentines had to work, and think, and sweat here at MetLife Stadium on a steamy Tuesday night, in the first of two Copa semifinals. They had to stomach the occasional early scare.

But they brushed aside Canada, 2-0, to reach Sunday’s final. Their clincher was perhaps the most subtle, plain goal Lionel Messi will ever score, his first of the tournament. And their breakthrough, midway through the first half, was straightforward — literally.

It required only two passes, from center back to central midfielder, then central midfielder to center forward. The first, from Cristian Romero to Rodrigo De Paul, was harmless. But the second found Argentina’s Canada killer, Julián Álvarez.

His first touch was excellent. His second left Canadian defender Moïse Bombito on the grass. His third beat goalkeeper Maxime Crépeau, and put Argentina ahead.

It was Álvarez who had broken through three weeks earlier, when these two teams met in the 2024 Copa América opener. On that night in Atlanta, Canada lasted 48 minutes. Here, it lasted only 22.

In those 22 minutes, the underdogs were frisky. They detected openings. They sprung forward on the counter. They threatened.

But they didn’t quite have the quality to pounce on opportunities. And once they conceded, they were toast.

Messi, with a classic feint and a right-footed shot, nearly buried the Reds right before halftime.

Some five minutes after halftime, he did bury them.

He got off the mark at the 2024 Copa América, ironically, with one of the most Cristiano Ronaldo goals of his glittering career. He slid a pass to De Paul. He continued his run. After some penalty-box pinball, he stabbed his foot at an Enzo Fernandez shot, and half-poked, half-caressed it into the net.

He glanced at the assistant referee, unsure whether he was onside. But he was, so he gently leapt into Enzo’s arms, and felt a feeling he hadn’t felt in a competitive Argentina game since October.

He had looked relatively pedestrian in three prior 2024 Copa América games. And frankly, Argentina had as well.

La Albiceleste looked vulnerable in that opener against Canada. They needed a late and lucky Lautaro Martinez goal to beat Chile. They rested starters in a meaningless group finale against Peru. They then needed a penalty shootout — and a heroic goalkeeper, Emiliano Martínez — to survive Ecuador in the quarterfinals.

So they entered this semifinal as unproven as a world champion can be. At times, they seemed to lack attacking ideas.

But they had enough to beat Canada again; they were occasionally sloppy but sufficient.

They have had enough to reach a third consecutive major tournament final, where they’ll meet their first mighty opponent of the summer, either Colombia or Uruguay.

Whether they have proved anything yet isn’t all that relevant. They are 90 minutes away from another title.