In the Champions League, the smallest error can cost you an entire tie. Unfortunately for Barcelona, it wasn't a small error and it did end up costing them a spot in the semifinals.
A red card for center-back Ronald Araujo in the 29th minute left Barcelona down to 10 men. A situation PSG took full advantage.
Up 1-0 following a goal from Raphinha, Barcelona looked poised to go through despite the dominance from PSG in the opening minutes. The Catalan side were defending well and demonstrated that it only took the tiniest opportunity in attack for them to score.
But Araujo's foul on Barcola all but threw Barcelona's plans out the window.
PSG equalized shortly before the end of the first half. Had Barcelona been able to hang on to the lead at the break, perhaps the attitude and belief would have been different. That didn't occur, however, and PSG scored three more in the second half to win 4-1 on the night, 6-4 on aggregate.
"We are annoyed," Xavi said after the match. "The red card marked the tie. We were well organized 11 vs 11. It completely changed everything. For me, it's too much to send off there."
The pressure of the situation got to Xavi as he let out his frustration at the referee in the second half after he whistled a foul on Frenkie de Jong. He was sent off and didn't hold back at expressing his displeasure at the referee's performance.
"The referee was really bad. I told him, he was a disaster. He killed the tie," Xavi said. "I don't like speaking about referees but it has to be said. I don't understand it.
It's not good going down to 10 players and from that point on, it's another game. For as much as we speak, the red card marks everything."
For Barcelona, the loss stings a bit more given the way they played the first leg and how they were playing before the red card.
The red card not only meant they loss their best defender in Araujo, but Xavi also had to sacrifice arguably their best attacker in Lamine Yamal to bring on another center-back. With only Raphinha and Robert Lewandowski up top, getting another goal was going to be a struggle. Though Barcelona did end up creating a couple of chances in the second half that could have made things more interesting.
In any case, it's another disappointing exit from the Champions League for Barcelona. If there is a silver lining, it's to take heed in the fact they competed well against a side many felt they didn't stand a chance at beating. Though it's going to be little solace from here until the end of the season.