Champions League: Who holds the aces before second legs?

Champions League second legs are finely balanced after tense first legs. Who really holds the aces ahead of next week's quarter-final deciders?

Arsenal, Bayern, PSG and Atletico all won their respective first leg encounters. Will that be enough to get them through? (Photo credit: GOAL)

The first legs of the Champions League quarter-finals taught us many lessons. They're not new ones, to be honest; however, they're worth dissecting.

Two Premier League teams went into the last eight contest. 

Three La Liga teams survived the round of 16 expedition, while we got one team from the trio of the German Bundesliga, the French Ligue 1, and the Portuguese league.

On the balance of current form and pedigree, there were no real surprises in what we saw over the past two days in the Champions League. 

What we don't know is what to expect next week when the sides square up again in their respective second legs.

Real Madrid and Bayern Munich served us a show. 

We expected nothing less from the most-played fixture in the history of the competition. 

It's delicately poised, with Bayern taking a one-goal advantage home; we expect Real Madrid to remind everyone they're the record champions.

Bayern had a series of chances to kill off their hosts in the first leg. 

A combination of poor finishing and decent goalkeeping kept the Los Blancos in the tie. 

Bayern can be said to be lucky as well, with Manuel Neuer rolling back the years to deny the hosts.

Arsenal beat Sporting Lisbon in Portugal to plant one foot in the semifinals. 

It wasn't a vintage performance by the Gunners, but when you're a top side, you'll always find a way to win difficult games.

Sporting was organized and could even have scored. 

David Raya denied the hosts a couple of times before Kai Havertz found the back of the net at the death. 

You wonder what could have been had Mikel Arteta handed David Raya the cup final two weeks ago.

Sporting Lisbon must be brave at the Emirates. 

It's going to be a tough game, but sitting back as they did in the first leg at home won't help much. 

When they do get their chances, they must ensure they take them.

Liverpool would look at the 2-0 loss in Paris and feel a sense of hope. 

The Premier League champions were battered in possession, but their hosts couldn't get past the goal line more than twice with some poor finishing from Ousman Dembele and Desire Doue.

2-0 isn't too much to deal with by a top side, but can you call Liverpool one on current form? 

Alexander Isak returned for the Reds and could be a huge boost in the closing stages of the season. We keep an eye on this one.

The final game of the round was at the Camp Nou, where Barcelona lost to Atletico Madrid. 

The hosts were brave even in the face of a red card to Pau Cubarsi. 

Atletico scored from the resulting free kick before Alexander Sorloth added the second goal in the second half.

Barcelona can overturn a 2-0 deficit without a fuss, but with the "haramball" that is accustomed to Diego Simeone, are we in for a show next week? 

It's tough to call across grounds in the Champions League however, we keep our fingers crossed.