19th April 2016.
Not too long ago, we were speculating about Barcelona winning a second treble in a row, or about Paris Saint Germain taking what they've done in France the last few years and translating it into their first-ever Champions League win. Both of those narratives were dashed against the rocks in the quarterfinal rounds, where Barcelona crashed out of the 2015/16 Champions League in jarring fashion and where PSG fell in an upset to Manchester City.

Now, with just four teams and two rounds remaining in the competition, the stakes have been ramped up another few notches. What happened for the UCL's once-guaranteed frontrunners, and what's next for Europe's most prestigious club football tournament? Read on to find out.

Barcelona's Downfall

Heading into the quarterfinals, FC Barcelona seemed like the safest of bets to charge right on through to the semis. After all, Barca have advanced to the semifinals of the Champions League in seven of the last eight seasons, going on to win three of those seven titles. Add the fact that the Spanish soccer club dominated last year's UCL en route to a treble victory and there was no reason to doubt Luis Enrique's side. They'd even handily dispatched their round of 16 opponents, beating Arsenal 5-1 to win their place in the quarters.

Then Barcelona strolled straight into one of their worst months in memory. Following a sloppy March 20th match against Villarreal-where Barca conceded a draw thanks to a second-half own goal from Jeremy Mathieu-the football club hit a shocking April slump. They lost El Clasico at home; they lost an away game at Real Sociedad; Lionel Messi seemingly lost the ability to score goals; Neymar struggled.

Indeed, since their March 16th second-leg round of 16 win against Arsenal, Barcelona have looked like a shell of their former selves. Only Luis Suarez has held things together, scoring two goals in the second half to give Barcelona a 2-1 win in the first UCL quarterfinal match against Atletico Madrid.

Playing on their home turf, Atletico Madrid erased Barcelona's early advantage, winning the second leg 2-0 on a brace from Antoine Griezmann. For Barca, it's déjà vu of what happened two years ago, the first time they were drawn against Atletico for the Champions League quarterfinals. The two teams drew in the first leg, but Atletico won at home to earn the spot in the semifinals. 2015 treble or not, Barcelona are out of the semifinals for the second time in three years.

The Rest of the Quarterfinal Action

Paris Saint Germain also faced a rude awakening in the quarterfinals, drawn against a second consecutive English opponent after eliminating Chelsea in the round of 16. Manchester City seemed to be at a disadvantage against the French giants, who have already secured their fourth straight title in Ligue 1. Considering Man City's recent struggles in the Premier League, the Parisians were the clear pundit's choice to reach the semis.

Playing at home in the first leg, PSG had an opportunity to establish an early lead. Manchester City scored first, but the hosts went on to dominate the possession and score two goals unanswered. However, a 72-minute goal from Fernandinho equalized the score for the Sky Blues and stole a win right out from under Paris Saint Germain.

From there, Man City merely had to win at home (or hold their opponents to a scoreless stalemate or a 1-1 draw) to earn a place in the semifinals. They opted for a win, edging into the lead with a 76-minute goal from Kevin de Bruyne. It was enough to win the game for England's last remaining UCL contenders. It also marks the fourth year in a row that PSG have bowed out of the Champions League after the quarterfinals.

If the Barcelona and Paris Saint Germain eliminations were surprising, experts at least got validation in watching the other two quarterfinal matchups shake out "according to plan." Bayern Munich eliminated Benfica to reach the Champions League semifinals for the seventh year in a row while Real Madrid beat Wolfsburg to secure their semifinal spot-a big improvement over last year's round of 16 elimination.

To be fair, though, both Bayern Munich and Real Madrid faced tougher challenges in the quarters than most fans expected. Bayern beat Benfica 1-0 in the first leg but settled for a 2-2 draw in the second. Real Madrid, meanwhile, lost 0-2 to Wolfsburg in the first leg and required a hat trick performance from Cristiano Ronaldo to win the second leg and avoid elimination.

The Semifinal Draw

The surprises of the quarterfinals lead to a semifinal draw with no obvious frontrunners. If the last round taught us anything, it's that nothing is guaranteed in this ultra-competitive soccer tournament-not even a treble-winning team staying in contention. In other words, while these two semifinal matchups might look predictable on paper, they are anything but.

The draw has pitted Manchester City against Real Madrid and Atletico Madrid against Bayern Munich. Conventional wisdom would likely point toward Real Madrid and Bayern Munich as the teams bound for the championship match. After all, both football clubs have won the Champions League before (neither Atletico Madrid nor Manchester City ever have), and their most recent titles came in 2014 and 2013 respectively.

Manchester City vs. Real Madrid

Then again, having just survived some seriously tough quarterfinal rounds, Manchester City and Atletico Madrid might have the momentum necessary to force an upset or two. In the Man City-Real Madrid match, it's tough to doubt the Vikings based on their talent alone. A club with Ronaldo, Gareth Bale, Karim Benzema, James Rodriguez, Toni Kroos, Marcelo, and Luka Modric-to name a few-is never going to go quietly. Manager Zinedine Zidane has also honed Real into the most physical and technically sound shape they've been in since the last time they won a Champions League title.

Still, Real's quarterfinal loss against Wolfsburg shows that the soccer club, regardless of bulk talent, is not invulnerable. Manchester City won't win the possession battle, but as they showed against PSG, they don't necessarily need to win the possession battle to win the war. Real Madrid concede chances all the time, as evidenced by their Goals Against column in the La Liga. If Joe Hart can hold strong in the goal, there's a chance that City could make this round closer than most pundits are predicting.

If there's one good reason to doubt the Sky Blues here, his name is Cristiano Ronaldo. Ronaldo single-handedly saved his team from elimination in the quarterfinals. He's scored 16 goals in the 2015/16 Champions League-twice as many as anyone else in the tournament. Our bet is that Ronaldo takes the Vikings into the finals to fight for their 11th Champions League title.

Atletico Madrid vs. Bayern Munich

Though it's something of a shame that the semifinal draw didn't pair Pep Guardiola's current club against his future club (Bayern Munich vs. Manchester City), an Atletico vs. Bayern matchup promises to bring the thrills.

Just like Cristiano Ronaldo is a threat to Manchester City, the team of Thomas Muller and Robert Lewandowski will be the major hurdle for Atletico Madrid. Both men have scored eight goals in the Champions League so far-one more than Atletico's top scorer, Antoine Griezmann.

With that said, Atletico dismantled an even stronger offensive unit in the quarterfinals (Barca's Messi-Neymar-Suarez vanguard) and have enough defensive power to leave Germany's reigning champions a little worried. Manuel Neuer is frequently labeled the best goalkeeper in the world, but he's conceded six goals in the four knockout matches so far, whereas Atletico's Jan Oblak has only conceded two. One need only look at Atletico's Goals Against column in the 2015/16 La Liga to know that this team is very sound defensively.

Our prediction? Though conventional wisdom might favor Bayern Munich-particularly since Pep Guardiola is entering the "last hurrah" stage of his tenure there-we've got a gut feeling that Atletico Madrid is going to win the upset.

If our predictions are right, then we'll be seeing a rematch of the 2013/14 Champions League final, when the two Madrid clubs squared off and Real Madrid won a historic 10th UCL title. If we're honest, though, we'd rather see an Atletico Madrid-Manchester City final-if only because neither team has ever won the tournament before.

Tune in for the first leg of the Champions League semifinals next week. Manchester City will host Real Madrid on Tuesday, April 26th, while Real Madrid will travel to Atletico Madrid on Wednesday, April 27th.