The UEFA Champions League quarterfinals kicked off this week, and with it came plenty of drama to unpack, so let's review.

On Tuesday, Arsenal muddled their way to a 1-0 win at Sporting CP thanks to an injury-time goal, while Real Madrid and Bayern Munich traded punches and shots for 90 minutes, albeit with the Bavarian side holding a 2-1 first-leg lead to take back with them to the Allianz Arena.

On Wednesday night, Barcelona succumbed to Diego Simeone's trap and lost 2-0 at home, with Pedri coming off injured (or was it a precaution?) and defender Pau Cubarsí receiving a red card late in the first half.

Meanwhile in France, Paris Saint-Germain had umpteen chances to decimate a wobbly Liverpool team low on confidence and form, but had to settle for a 2-0 first-leg lead ahead of the return at Anfield next week.

So, what to make of it all? ESPN FC writers Mark Ogden, Gab Marcotti, Julien Laurens and Sam Tighe are here to break down the action as it happened and look ahead to next week's second legs.

- Kirkland: Real Madrid believe they can beat Bayern.

Are they right? - Ogden: Wasteful PSG leave door open for Liverpool in UCL - VAR Review: Was Cubarsi's red card deserved? Q1.

Does PSG's 2-0 win over Liverpool say more about the Parisians or Arne Slot? The Reds tried a drastic formation change and created nothing, with the entire thing seeming like it was just a matter of time until Luis Enrique's side blew the doors off the visitors' desperate rearguard.

It might well be the worst Liverpool performance under Slot, too ...

Tighe: Realistically, Liverpool felt doomed in this match before a ball was kicked.

A team this fragile, this flawed and this leaky late on in games cannot be expected to go to the Parc des Princes and pull out a result.

Slot seemed acutely aware that the usual plan would not work, so he changed it up and fielded three center backs in a 5-2-1-2-esque shape.

It seemed like the intention was to prevent PSG completely taking over by using wide combinations while utilising Dominik Szoboszlai's energy in support of the attack, but the consequence of the shape change was that Vitinha and Co.

had all the time in the world to run the game from central positions, where Ryan Gravenberch and Alexis Mac Allister seriously toiled.

I'm not sure we learned anything about the Reds (except that Alexander Isak is fit again), but we did have it confirmed that PSG, the reigning European champions, are humming at just the right time of the season.

Marcotti: We can keep blaming Slot for everything (it's his fault the Strait of Hormuz hasn't reopened yet, isn't it?) and, sure, trying to surprise PSG with a formation you've never played or trained before seems silly with the benefit of hindsight.

But what's the alternative? Doing nothing, trying to play them straight up and getting hammered? They did that at Manchester City in the FA Cup just a few days ago.

The main issue I have with Slot is waiting until 12 minutes from time and then making a quadruple substitution (and none of the subs being Mohamed Salah).

And then being lucky the final score was 2-0, rather than being four or five down.

Do we want to blame him for the fact that Liverpool's first shot on goal of any kind came four minutes into the second half? OK fine.

Go ahead that's all his fault too and not down to the recruitment.

The fact of the matter is that Liverpool are still in this tie at 2-0 down, so he can hang his hat on that.

He may not be a genius but making this all about him and his shortcomings isn't fair.

Ogden: Liverpool are absolutely still in this tie and Luis Enrique should be furious about that.

He seemed quite relaxed about it during his post-match press conference, but PSG should have won by five or six and their failure to do so might come back to haunt them at Anfield.

PSG were so dominant that they started with the tricks and the flicks and that's why Luis Enrique should be angry with his players.

Just get the job done and then play around.

Maybe the PSG boss' sanguine reaction was because he knows that this Liverpool side are beginning to stink the place out and a group of players who perform so poorly are unlikely to flick a switch and turn it on so much that they salvage the tie at Anfield.

Slot tried a new formation because he has no legs in midfield and his forwards don't work hard enough.

It didn't work in Paris and Liverpool are unlikely to turn it around next week, but they still have a chance and that's pretty much all Slot was hoping for.

Laurens: PSG did what they have been doing at their best for over a year now.

So, we have to look at Slot and the mess that he made again on Wednesday.

His back five was total nonsense, he encouraged his team to just defend (only three shots, none on target and 0.18xG) and the players -- who have been poor all season long (and that's not just on Slot) -- looked lost.

Speaking of lost, feels to me that Slot has lost the team.

Look at the expressions of Florian Wirtz and Szoboszlai when they were subbed off.

Look at Salah's face on the bench once he realised he was not coming on.

The issues at the club are more than just the manager, but he is not helping himself or his team either.

He has been struggling all season to find the right formula to fix the Reds' issues, and he has failed to find a solution so far.

Liverpool should have lost 5-0 in Paris and were lucky to escape with a lesser scoreline.

That's not Liverpool we know.

Real Madrid and Bayern offered up an entertaining first leg that saw 40 combined shots and 4.96 xG between the two sides.

In the end, was it the goalkeeping that made the difference? Manuel Neuer really turned back the clock with a stunning performance to deny Kylian Mbappé time and time again, while Andriy Lunin arguably could have done better.

Or was it something else? Laurens: We have known since the start of the season that Real Madrid had to avoid two specific players getting seriously injured because of how losing either or both could derail their season.

The first one was Mbappé, and the second one was Thibaut Courtois.

Without the Frenchman, the Merengues did manage to stay on track, but not having the Belgian for a game of this magnitude was a massive blow, and Madrid paid for it.

Lunin is a good back-up keeper, but he's not good enough to win you games (or prevent you from losing) like Neuer can be -- and like he was on Tuesday night at the Bernabéu.

Courtois would likely not have conceded Harry Kane's goal, and it's fair to say he certainly would have made the hosts' defence stronger.

For Neuer, at 40, it's another proof that he is one of the greatest keepers of all time.

SC Freiburg in the Bundesliga doesn't interest him so much anymore.

Give him Real Madrid under the lights in the Champions League and he is your guy! Marcotti: The goalkeeping was a big part of the story, sure.

Juls is right: there's no way Courtois concedes that goal to Kane, while two of the three saves Neuer made off Mbappé were truly special.

Even if you're not a Neuer fan, you have to appreciate that given his injuries, given he's now 40 and given what happened last time he played at the Bernabéu, when Joselu scored twice.

That said, I think an equally bigger part of the story is Bayern's failure to hang on to a two-goal lead.

They absolutely battered Real Madrid in the first half and, I think, should have been more than just a goal up.

Then, at 2-0, with the fans freaking out and Madrid boss Alvaro Arbeloa making tweaks, you have to see the game out.

There's a huge difference in coming back from two goals down on the road compared to one goal.

You can't give up that many chances.

The only mitigating factor, I guess, is the Bernabéu and the old trope by which time seems to magically turn more slowly when Real Madrid....