Now it's PSG's turn to miss a chance!

Fabián Ruiz miscues another header.

Both teams lacking precision in and around the box.

Still 1-0 Dortmund with three minutes plus stoppage time remaining.

No, he didn't score. He saved PSG, from what surely would've been a 2-0 deficit, with a sliding block on Julian Brandt.

Jadon Sancho slipped Brandt into the box with a clever little pass, and Brandt, for a fleeting moment, looked more likely to score than not. But Marquinhos came flying in from the blind side, stretched out his left foot, and foiled Brandt.

What a miss. PSG created perhaps its best chance of the game. The ball rolled into the lap of Ousmane Dembélé at the penalty spot. His blazed his right-footed shot a few feet over the bar.

Yikes.

After a pretty frantic 30 minutes, the game has now calmed down a bit.

PSG, finally, enjoys a sustained spell of possession. Then Dortmund gets a turn.

0-0, approaching the 80-minute mark.

PSG just brought on Randal Kolo Muani, who has spent most of his career so far playing as a central striker.

Mbappé, meanwhile, is often most effective on the left wing.

But Mbappé is still playing as the central striker, and Kolo Muani is out on the left.

We'd love to hear Luis Enrique's reasoning for that.

(Update: As we were writing, Mbappé floated out to the left, and very nearly created a goal.)

The hosts were clinging to their lead between Minute 46 and 58 or so.

Now they have been all over PSG for a good 10 minutes, and created multiple high-quality chances. No more goals, though.

Ooooh boy.

Julian Brandt floated a cross to the far post. Füllkrug, it seemed, was about to rise to meet it — and then he got a nudge in the back from Nuno Mendes.

It was the type of contact that, in a vacuum, wasn't all that forceful. But it absolutely put Füllkrug off, and it absolutely was not an attempt to play the ball.

That, in my opinion, should've been a penalty. But the referee and VAR say no.

Füllkrug misses this time.

Created, against the run of play, by an electric burst down the right from Jadon Sancho.

Still 1-0, with 30 minutes plus stoppage time to go in this first leg.

Marquinhos just hit the pass of the night. An exquisitely shaped cross — somehow, from the right center back position — that hopped onto the head of Fabién Ruiz.

Ruiz couldn't quite direct the header on goal. And to be fair to him, the height of the ball and the angle were awkward. But still, big chance.

Kylian Mbappé rattles the right post. Ten seconds later, Achraf Hakimi strikes the inside of the left post.

Both shots caromed back across the face of goal, but stayed out.

Incredible. Dortmund's lead holds firm — by a matter of inches.

It'll be fascinating to see how much PSG chases this game. Do they play as if they're behind? Or would they be perfectly happy going back to Paris with a 1-0 deficit?

Admittedly, "his best" is an impossibly high standard, but that was subpar half from Kylian Mbappé.

Some credit goes to Dortmund. Defenders have crowded him out a few times.

But on the few occasions he's found space, he hasn't been sharp. One sequence, around the 33rd minute, stood out. He received the ball in a central position, in transition, with runners to both his left and right and a numerical advantage. He overhit his pass out to the left, and spoiled the break.

Borussia Dortmund is ahead, 1-0, and ascendant.

Still a long way to go, and a one-goal loss tonight wouldn't be all that bad a result for PSG. But the Parisians need to recover, and make sure this doesn't get worse.

Füllkrug's technique here is incredible. Strikes straight through the ball with his weak foot. Keeps it low, skimming off the grass, flying inches off the ground past Donnarumma.

That, folks, is what soccer people call a "daisy cutter."

And this is precisely why Füllkrug has risen to prominence in German football.

Niclas Füllkrug!

Dortmund leads.

The Signal Iduna Park is rocking.

PSG's metronome, defensive midfielder Vitinha, is helping the visitors gain some control here.

He's so quick and clean on the ball. Spraying some passes. His positioning has also been great over the past 15 minutes.

PSG much more comfortable now than it was in the early exchanges.

Dortmund's first real chance of the game — a close-range, bad-angle shot from Niclas Füllkrug, saved by Gianluigi Donnarumma — is a pretty good representation of how they'll win this game, if they win it.

Won a duel at midfield. Julian Brandt, their creator, picked up a loose-ish ball. And almost immediately, even without overwhelming numbers getting forward, the break was on.

No real chances through 10 minutes, but Dortmund's press has been aggressive and effective.

Karim Adeyemi, an energizer bunny of a winger, has been lively down the left.

PSG looks relatively comfortable, though. Ousmane Dembélé gets the first shot of the game, from 25 yards out, and drags it well wide.

What an atmosphere. What an occasion. Flags waving, songs ringing.

All of this is why we love this sport.

This matchup, in many ways, is talent vs. aura, atmosphere and history.

PSG has never won a Champions League or European Cup. It has never won a game of any kind at Borussia Dortmund — whose home-field advantage is one of the most vaunted in Europe.

But, on paper and in practice, PSG is a better team. Mbappé will be by far the best player on the field.

We'll see which side of the contrast carries the day.