A free-kick from Ivan Rakitic in the 12th minute got Barcelona underway at Huesca's Estadio El Alcoraz before Andres Iniesta and Pedro also scored before half-time, while Rafinha's 71st-minute strike wrapped up the first-leg victory.
With a number of younger players in the starting line-up, including Douglas Pereira, Marc Bartra and Sergi Samper, Luis Enrique paid tribute to Barcelona's professionalism and commitment against their Segunda B opposition.
"These games can become difficult," he said.
"Even though the pitch was in perfect state to play in, sometimes the opponents are more motivated than we are.
"But I think that we were really intense and we played a really serious game.
"I think in the first half we decided the tie and in the second half we were a bit more up and down but you can understand that."
Barcelona will host the second leg on December 16, while their next match will be the Derbi Barceloni against Espanyol on Sunday.
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