The midfielder struck after five minutes at the Vicente Calderon as Atletico won the quarter-final, second leg 1-0 to go through to the last four 2-1 on aggregate.
It was no more than Diego Simeone’s men deserved, especially after a lightning start during which the hosts hit the woodwork on three occasions, with Barca’s defence looking lost without experienced defenders Gerard Pique and Carles Puyol and goalkeeper Victor Valdes.
It meant Atletico advanced to their first Champions League semi-final since 1974 and Koke is dreaming of going all the way.
He told reporters after the game: “(To be in the semis) after 40 years is spectacular, this team has no limits. Let’s make the people keep dreaming.
“We were clear winners. The goal was very important because it helped the team reach the semis. Our work in the tie has been spectacular.”
Atleti will line up alongside holders Bayern Munich, Chelsea and Real Madrid in Friday’s draw.
Koke added: “The next team we will play will be very difficult, but we have eliminated one of the best, if not the best.”