After their 5-1 hammering at the hands of Holland in their opening match, del Bosque was looking for a response in the Maracana, but instead he saw his side's hopes of progressing from Group B vanish with defeat.
First-half goals from Eduardo Vargas and Charles Aranguiz secured victory for Chile, and del Bosque admitted they deserved their win.
"We have no excuses," said del Bosque.
"We were too slow, timid from the start today. It's a sad day for all of the players and time to think about the future.
“We played two games, and were not able to be better than Holland or Chile, so we are out of the World Cup.
“We thought we had very good chance, good players. But the reality is different."
Goalkeeper and captain Iker Casillas added: "It is hard to explain what happened. I ask for forgiveness. We did our best and did not want to disappoint people.
"There is no option but to look into the future, think about the next game and do our best. Holland and Chile were better than Spain."