The 2013 Champions League round of 16 had a lot to love about it.
Manchester United and Real Madrid going blow-for-blow at the Bernabeu Stadium; Bayern Munich establishing themselves as potential frontrunners with a huge win over Arsenal at the Emirates. And who could forget AC Milan's stunning upset over Spanish giants Barcelona.
There was clearly plenty of good and enjoyable takeaways from the first leg of these matchups yet, at the same time, each time had it's own disappointments and frustrations.
Some might have been more pronounced than others, but every team had them in their first leg. Read on to see what their biggest disappointment in the Champions League was.
It's pretty tough to fault a team that played a near-perfect match against world football powerhouse Barcelona—toppling the heavily favored Spanish giants 2-0 at the San Siro.
Yet if there's one thing that Milan will be disappointed with, it has to be their finishing on the night.
Yes, they netted two goals—the second of which particularly showed some excellent team movement—but they really should have netted at least another one here. Three notable chances went begging in the first half for the Rossoneri, which could well be the difference in the second leg.
Stephan El Shaarawy blew a chance after drubbing too far when the scores were still tied, and then he was inches away from connecting with a cross moments later. Kevin-Prince Boateng also nearly netted off a short-ish corner, which Milan could have benefited from if they had someone on the back post.
Two goals is obviously a huge advantage to take into the Nou Camp, with the pressure right back on Barcelona to show just how good their attack can be. But two goals is not insurmountable—especially given their attacking depth—and Milan could well live to regret not making it three or four here.
Much has been said about the Gunners' lackluster performance at home, but the majority of it stemmed around the fact that the London club simply didn't have any direction in their attack.
Mikel Arteta, Jack Wilshere and Santi Cazorla were simply a passing trio that didn't get the Gunners going forward, with their only goal in the match coming from a Bayern Munich error.
Arsenal dominated possession but didn't have the direction and purpose to their attack until after they netted their first goal. But by then, Bayern already had two of their own and the match was all but over.
It was like watching tiki without the taka—possession without the attack to complement it.
Watching Barcelona play against AC Milan, it was just bizarre.
The Spanish giants had their usual possession, and they had their usual field position, but they simply refused to shoot the football when they had the opportunity.
The times that they did have shots, they came awfully close to scoring, but those times were simply too few and far between for Barca.
For a team that boasts an incredible goals-per-game ratio in La Liga, to be out-shot on the night by Milan despite having 67 percent possession was simply horrendous.
It wasn't necessarily Milan's parking the bus that won it for them here; it was Barcelona's inadequacies to simply get attempts on goal when they had the chance.
Bayern Munich's defense has been so strong all season, with the German giants remarkably not conceding a single goal since the start of the New Year in 2013.
All of that changed here, however, when Manuel Neuer and the Bayern defense simply broke down in communication, and Lukas Podolski was gifted one of the more easy goals he'll ever score.
It will hardly matter, with Arsenal incredibly unlikely to win 3-0 or 4-1 in the return leg in Germany, but even still, Bayern should not have allowed that soft goal.
Against the top teams in the tournament, those goals will count.
Borussia Dortmund are a giant team at home, with the German champions boasting a prolific record in front of the Yellow Wall and their passionate home fans. However, away from home, that defensive solidity simply isn't as existent, and the German side can be exposed at the back.
Shakhtar did that twice in this one and really should have finished with three or four goals—as well as only allowing one at the other end themselves. Had they been more disciplined (which we'll get to later), Dortmund could have well been in trouble and had some work to do in the second leg.
As it stands, however, they carry a crucial away-goal advantage into the return leg at home, which they'll likely progress through with a victory.
Yet their form away from home still stands as a big concern for Dortmund here.
Celtic were the Cinderella story of the Champions League—somehow progressing through to the Round of 16 from their tough group and beating giants Barcelona in the process.
However, up against a dominant Juventus team in the knockout rounds, it seems this fairytale isn't going to end happily ever after for the Scottish legends.
Juve simply ran riot over Celtic, who will no doubt live to rue the two late goals that they allowed to the Italian league leaders. Surely a three-goal advantage, playing at home and having the away-goal edge make the return game now a mere formality for this pair?
Celtic simply looked like a deer in the headlights—completely and utterly stunned.
For all the attacking that Schalke did against Galatasaray, it was the home side who probably should have finished with a 2-1 or even a 2-0 victory on the night.
Hamit Altintop hit the bar on the most simple of shots, and Dany Nounkeu had a chance early that could well have put the visitors to bed in this one.
They did not, however, and Schalke were not only able to work their way back into the match, but also grab a crucial away-goal advantage heading into the second leg.
The Turkish giants may well live to rue those misses in the second leg.
OK, so it's pretty hard to fault Juventus after their performance against Celtic.
They were ruthless in attack and dominant in defense, with their strong squad seriously looking like taking them a long way in the premier European tournament.
If we had to find a disappointment, it's probably in the yellow cards that the Italians picked up, with several players now potential suspensions for their next match if they pick up yellows again.
Simon Padoin, Stephan Lichtsteiner and Claudio Marchisio all received cautions, though with the lead that they have and the depth on hand, the trio could probably all be rested for the return leg anyway.
Like I said, it's pretty hard to find a fault with Juventus here.
Malaga have been incredibly tough to break down defensively in the Champions League this season, and they had not trailed in a single matchup until their fixture against Porto.
And whilst the Spanish giants weathered most of the storm, Joao Moutinho's strike was enough to give the home side a 1-0 lead and something to play with heading into the return game.
Had Malaga been able to hang on for a 0-0 draw, they'd have been highly favored to move through to the next round of the competition. And whilst they might still do so, the goal certainly puts the pressure back on the Spanish club to find the back of the net in their next fixture.
That, or suffer elimination from the tournament.
Manchester United did remarkably well to keep Real Madrid at bay for 90 minutes here—only allowing the one goal to Cristiano Ronaldo—and taking an away-goal advantage back to Old Trafford.
However, star striker Robin van Persie really should have made it a win for the Red Devils on the night, with the Dutchman squandering several key chances to put his side in front.
A header onto the bar and a horrendous scuffed shot that was cleared off the line spring to mind immediately, as does a shot in the waning seconds of the match that brought about a huge save from Diego Lopez at the back from Madrid.
Had RVP netted at least one of those, United would have been the favorites heading into the return game. Now, the pair stand evenly positioned once more.
Will they live to rue those misses?
Paris St. German scored a key win away from home against Valencia—running out 2-1 winners on the night despite doing a lot of defending and being down to 10 men after Zlatan Ibrahimovic was sent off.
Yet despite all of that, the French giants should have kept this one at 2-0, with Adil Rami's stoppage-time goal giving the Spanish club the potential to perhaps stay alive in the competition.
It was a free kick that should have been defended but wasn't, and PSG could well turn out to regret the goal in the return fixture in three weeks' time.
Especially without Ibrahimovic to carry their attack.
Porto dominated Malaga at home in their Champions League Round of 16 clash, and whilst they did walk away with the win, they really should have netted more than just the one goal in this one.
The Portuguese club had 62 percent possession and a staggering 16 shots on goal compared to just one from the visitors, and yet they only scored the one goal in the process.
Malaga are a tough side to break down—particularly at home—and will certainly challenge Porto throughout the second leg of their tie. And that's when the Portuguese side could well end up regretting their wasteful finishing in the first leg of their encounter.
This picture suggests that Karim Benzema played for Real Madrid against Manchester United.
Those that watched the game could have been forgiven for thinking otherwise, however, with the French international simply nowhere to be found when Madrid needed him to step up.
Angel Di Maria offered far more of an attacking threat than Benzema did here, who was simply outplayed by the two central defenders from Manchester United in the first leg.
Madrid needed to score and had several chances to do so in this one, but they could not break the deadlock—largely in part to the fact their striker was simply MIA.
Will he get a start again in the second leg?
Shakhtar Donetsk drew a tough opponent for the Round of 16 in Borussia Dortmund, especially given the home dominance from the German champions in the past few seasons.
Thus they knew that taking a lead into the second leg would be pertinent to their chances, and the Ukrainians looked on course to do so in the first leg with a 2-1 lead in the bag.
That was, until they simply switched off from a corner and allowed Mats Hummels one of the most regulation headers that you're ever likely to see from a set piece. The defending was simply non-existent, and with the goals now tied and the away-goal rule in full force, it could prove to be the end of Shakhtar in the tournament—that one late goal to Hummels in the first leg.
Schalke might have been the away team in this one, but with Galatasaray no lock at home and the German team playing well on the road in the Champions League so far, a 1-1 draw on the night really wasn't the greatest thing for Schalke to emerge with.
Sure, they'll be happy to take it and have the away-goal advantage heading into the return leg, but given their dominance throughout the second half, they really should have won this match.
They won the possession battle and finished with 14 shots to nine, but could not take their advantage that step further and break down the Turkish defense in this one.
Those misses could turn out to cost them in this Round of 16 tie.
At home, against a PSG team without Thiago Silva, Valencia were really very poor.
The 2-1 scoreline on the night didn't do justice to either PSG's dominance or the Spanish club's lack of direction in attack, with their goal coming from a set piece in stopping time.
Hardly what you'd call attacking direction.
Valencia desperately need to improve in the second leg if they're to progress here (obviously), and that seemingly starts with getting some better drive through the middle.
Or at least having some sort of idea what's going on in attack.
What did you think was each team's biggest disappointment in the UCL?
Comment below or hit me up on Twitter: Follow @dantalintyre