Barcelona coach Luis Enrique admitted his side's first win in Champions League Group E came at a price with Andres Iniesta set to join Lionel Messi on the sidelines.
Iniesta went off with a hamstring injury before late goals from Sergi Roberto and Luis Suarez denied opponents Bayer Leverkusen a famous victory at the Nou Camp.
The Germans led through a 22nd-minute strike from Kyriakos Papadopoulos and had chances to extend their lead before Enrique's men turned the tie around in a 92-second spell.
Enrique described the injury to Iniesta - which follows the news that Messi is likely to be sidelined for up to two months with a leg injury - as "terrible news", adding: "These are thorns in our side we have to shake off.
"My players deserve a huge amount of credit for turning around a very difficult situation. It was a tough night - the second game without our best player and our second win."
Barcelona's win moves them to the top of the pool with four points from their opening two matches after an opening draw at Roma, but the top three sides are separated by a single point.
Enrique added: "It is always tough to overcome the kind of pressure Bayer put on us tonight.
"I said when we were drawn in Group E that it was a tough group. I'm really happy for the win. It's time to celebrate with my family, and on to the next one."
