Copa América: Lionel Messi unlocks Canada, Argentina opens with a shaky win

After the latest missed chance, Lionel Messi went down.

Canadian center back Moïse Bombito flew into a tackle, and caught Messi flush in the ankle.

Messi is up now, but limping. He'll likely stay in, but that'll hurt. And it was scary.

Jacob Shaffelburg dipped past an Argentine defender into the big, and got taken down.

The referee seemed to bring his whistle halfway to his mouth ... then didn't bring it all the way.

On replay: It was absolutely a foul, but probably just outside the box, so there's nothing the VAR could do.

Remember when Pelé wowed at the World Cup even when he sent shots wide? Messi just did something similar. He sat two Canadian players down with one feint on a break, and nearly scooped the ball into a gaping net, but his clever shot was blocked.

At the other end, Jonathan David just flashed a header a few yards high and wide.

Still 1-0 to Argentina.

To the untrained eye, Argentina's goal was the umpteenth example of Lionel Messi's greatness. His through-ball to Alexis Mac Allister was one that nobody else on the field could see.

But I'm not sure Messi saw it either.

He seemed to be looking for Julian Álvarez's feet. Alvarez, though, made a diagonal run, so Messi's pass went into no-man's land ... which Mac Allister happened to be running into.

Messi to Mac Allister, who gets cleaned out by Canadian keeper Maxime Crépeau.

It would've been a penalty, but Mac Allister's touch fell right to Julian Álvarez, who finished well.

1-0 to Argentina.

In Canada's two pre-tournament friendlies, they also held elite opponent scoreless for 45 minutes.

In the first, they got blown out by the Netherlands after halftime and lost, 4-0.

In the second, they held on for a 0-0 draw with France.

This third such game could really go either way. (Or, it could very easily go to Canada.)

All in all, a pretty good start for Jesse Marsch and Canada.

They'll be far happier than Argentina, both with the scoreline and the performance so far.

But, of course, the Argentines are still the favorites. They've had chances. They'll have more. And, well, they have Lionel Messi.

The temporary grass field that's been installed at Mercedes-Benz Stadium in Atlanta was a topic of conversation pregame, and even more so throughout the first 30 minutes of this game in Argentina.

It's a bit choppy and uneven, and sometimes seems to slow the ball down. Players don't quite seem as confident in their touch as they'd normally be. That iota of hesitation or discomfort can really make a difference.

This, so far, is a 50th-percentile performance from both teams.

If it continues apace, you'd expect Argentina to eventually find a few more chances and a goal. But there's no guarantee that the goal will come.

Canada also has firepower on the break, but Argentine defenders are so good at neutralizing the break with, among other things, tactical fouls.

Aside from one Argentine barrage, Canada has been ... fine. Not good, but fine.

Messi and Di Maria are dangerous. They always will be. But the Canadian setup is solid, and the underdogs have maybe settled a bit now.

Eight of this Argentina starting 11 also started the World Cup final 18 months ago.

Ten of today's 11 played in that unforgettable game.

The only one of today's 11 who didn't is Lisandro Martinez, who is very clearly an upgrade on 36-year-old Nico Otamendi.

So, yeah ... they're the tournament favorites for a reason.