Barcelona scored two goals away to Paris Saint-Germain in the Champions League this week, but thanks to a stunning second-half revival, those will be the only away goals that they take with them back to Camp Nou.
Having dominated possession and attacking chances throughout the night, Barcelona were again exposed at the back late in the match, with Zlatan Ibrahimovic and Blaise Matuidi both netting goals in the final minutes to bring PSG back on terms.
Barca went ahead early through Lionel Messi and appeared to have sealed the win when Xavi Hernandez converted his penalty in the 89th minute, making it 2-1.
But with the final kick of the game, PSG found an equalizing goal, and will carry plenty of self-belief with them in the return leg next week.
Read on to see the biggest storylines to watch in the second leg.
Can Barcelona's Defense Hold Up Once More?
After staring down a 2-0 deficit in the Round of 16, Barcelona showed against AC Milan that they are a truly potent force to behold at home—winning 4-0 on the night and, other than the last 10 minutes, not allowing their opponents any real goal-scoring opportunities.
Their defense was solid in that one, but after watching them fall apart at the back once more, big questions must remain about whether they can post a clean sheet in front of their home fans.
Barcelona will no doubt score goals—that's a given. And with the away-goal advantage in their grasp, Barca shouldn't see themselves fall behind at home.
However, as they've shown all season, they can be exposed at the back with quick long balls and attacking raids—strengths of PSG, with Lucas Moura and Ibrahimovic two key attacking weapons that can make that happen.
How Barca's defense holds up at home will decide who moves through to the Champions League semifinals—not how their attack operates.
No Lionel Messi?
Perhaps the biggest talking point of the night is that of Lionel Messi, whose departure in the second half was a huge cause for concern for Barcelona.
Especially since after that point the home side were able to gain much better attacking ascendancy and eventually score two key goals to tie the game.
Thus the biggest questions are how long Messi will be out for, how bad the injury is and whether or not he'll be right for the second leg. And frustratingly for all of us, the news about that won't be revealed until tomorrow (according to the Spanish club).
FC Barcelona @FCBarcelona
Messi sustained an injury to his right hamstring. He will undergo further tests on Wednesday to determine the extent of the injury. #FCBLive4/2/2013, 7:52:53 PM
Sky Sports also commented on how big the injury is for the Argentinian.
First time in 5 years Lionel Messi has started a game and not started 2nd half. Rumours of a three-week absence. Makes return v interesting.4/2/2013, 9:08:53 PM
His return (or absence) will be the biggest storyline of them all to watch in the second leg—especially given the repercussions it would have for Barcelona.
Can Ibrahimovic Thrive Back at His Old Club?
PSG striker Zlatan Ibrahimovic was the go-to man all night for the French club, which turned out to yield great success in the end. He was dominant in the air, and was more than capable of beating his man—forcing Barca to send two and sometimes three defenders his way.
If PSG are to fire an improbable upset at the Nou Camp, it would surely be Ibrahimovic to do it. And given his pre-existing relationship with the Catalan club and its environment, don't be surprised to see him have a big night against his former teammates.
We saw it when Manchester United's David De Gea went back to Spain to play Real Madrid; we saw it to a lesser extent but still notable as Juventus' Arturo Vidal returned to Germany to take on Bayern Munich. Will Ibrahimovic be another example of a player returning to his former breeding ground and showing the same skills that made him a household name there?
Ibra was never the marquee striker at Barcelona thanks to Lionel Messi.
But with the Argentinian wizard potentially out of the return game, expect the Swedish star to show the Catalan crowd just how much they missed out on.
He'll be Barcelona's biggest nightmare in defense, and he'll be the home of every PSG fan around the world. And as he's done in big games so many times throughout his career, the enigmatic striker may well just deliver for his team on the biggest night of them all.