"I've thrown everything. I didn't know if I was onside. I'm very happy," Roberto told BeIn Sports. "I threw myself on the ground and I saw the goalkeeper [Kevin Trapp] didn't stop it."

The hosts were up 2-0 at half-time through a Luis Suarez strike and a Layvin Kurzawa own goal, and Lionel Messi added Barca's third early in the second half from the penalty spot to give hope to those looking for a comeback.

But an Edinson Cavani goal at the 62-minute mark seemed to give PSG breathing room until a Neymar free kick and penalty minutes apart set the stage for Sergi Roberto's miraculous 95th minute goal to complete the rally and send Barca through to the quarterfinals.

"They say the fans are one more player, but today they were 10 more," Roberto added.

"In the end, this is also for them. Now to celebrate and think about the league game [against Deportivo La Coruna on Sunday]."

Sergi Roberto celebrates after scoring the Champions League match-winner against PSG on Wednesday.

Midfielder Ivan Rakitic said it was his team's belief that allowed them to pull off the "crazy" upset: "I cannot believe it. It was really impossible. [It's] 15-20 minutes after the game, it is crazy and unbelievable.

"Thank you to the team, to the people around the club and the fans. It was a really special day and it is hard to say something."

"The first game in Paris was hard for us, a lot of people spoke hard of our team but the reaction was special. It is history. We want to keep going on," Rakitic said.

"We had to believe, 4-0 was hard, but it is football. We saw it in the Super Bowl, what is possible in sport. Today was crazy. This is Barcelona, the best team in the world and we want to continue our dream in the UEFA Champions League."

Defender Samuel Umtiti was equally awed by the scope of the fightback and admitted it was the space afforded the team by PSG that allowed them to score six.

"I've never experienced anything like that. The coach asked us [before the game] if we'd already pulled off a 'remontada' and nearly no one said 'yes.' We did what the coach wanted. When we play with that attitude, we're very strong.

"Paris allowed us to play and we made them run around. We prepared well. The great teams pick themselves back up quickly when they fall."