Despite leaving senior figures Xavi and Xabi Alonso at home, Spain were rarely tested with Pedro scoring twice to add to strikes from David Villa, Sergio Ramos and Markel Susaeta.
The world and European champions were 3-0 up by half-time after Andres Iniesta had teed up Pedro and Villa to slot home before Pedro produced a classy finish for his fifth goal in his past three internationals.
Ramos then thundered home a wonderful free-kick nine minutes from time and debutant Susaeta completed the scoring for the visitors with an easy finish from Jesus Navas' cut-back.
However, the home fans were given something to cheer three minutes from the end as Gabriel Gomez dinked home a penalty after Cesc Fabregas had tripped Nelson Barahona.
"The balance between order and talent gave us the edge," Del Bosque told a news conference. "We took the game seriously, with a certain level of commitment, and our domination of the ball did not allow them many chances.
"We could have scored more goals in the second half but we made it easy for ourselves."
Spain's Chelsea midfielder Juan Mata was also satisfied with their efforts in hot and humid conditions.
He told reporters: "We played well, it was a good spectacle and we are returning to Spain feeling content.
"They are still in with a chance of qualifying for the World Cup and the weather conditions were not the best for us but we performed well."