The former Santos star leveled the scoring with a fine finish after Diego had previously gifted Atletico the lead and Iniesta - who set up Neymar for his goal with a superb through pass - has hailed the attacker's ability to create something out of nothing.
"As far as our goal is concerned, Neymar has that talent, that quality. With just one moment, one move, he can turn the game and the result," Iniesta told reporters. "We are delighted with his goal and now we have to ensure that it becomes significant in turning the tie our way."
The attacking midfielder then went on to stress that Barcelona remains optimistic about its chances of reaching the semifinals.
"None of us has any doubts about our capacity to win there, any doubts about our style of play or about our team," he said. "Now the tie remains open and we will travel to Madrid with our thoughts focused on making it to the semifinals.
"That it will be difficult, we know. But we will go to Madrid with every confidence of making it through."