Its new-look team was struggling without Lionel Messi and years of financial mismanagement looked to threaten the club's position at the top of European football.
But the team had started to show promise since club icon Xavi took up the reins in November, and Sunday was the biggest show of strength yet as it thrashed fierce rival Real Madrid 4-0 in the La Liga leaders' own stadium.
"I'm delighted, it's a night to enjoy," Xavi told reporters. "Barça is back."
"Today, we showed that we can fight against a great Real Madrid team that are on a roll and in their stadium.
"It is a great achievement to encourage us for the future of our project."
A brace from in-form striker Pierre-Emerick Aubameyang and goals from Ronald Araújo and Ferrán Torres silenced the sold-out Santiago Bernabéu as the Blaugrana rolled back the years with a dominant performance from the very first whistle.
Ousmane Dembélé, one of those expensive players that had been failing to prove his worth at the club, looked rejuvenated and caused Madrid constant problems with his pace.
Barcelona looked fluid and full of ideas while Los Blancos seemed lifeless and short of options. In truth, the visitors could have extended their lead further if it wasn't for Thibaut Courtois in goal.
"I'm happy because we were much better than Real Madrid. We have played a spectacular match," Xavi added.
"I'm enjoying it because more than just being Barça's coach, I am a lifelong club supporter, so nights like this are those you never forget."
Barcelona is now unbeaten since January 20 and sits third in the league table -- Madrid leads Barça by 12 points, having played one more game.
It was also the first time in three years that Barcelona managed to beat its biggest rival, a sign of just how poor the club has been in recent times.
"We didn't expect this result, but our objective was achieved. We came to win and show what we are worth," Barça midfielder Sergio Busquets told reporters.
"If we still have a small chance to make a run for the title, we will fight until the end. It's very difficult but in football anything can happen. We are Barça."