Bulgaria hung with Spain for 20 minutes, but the Iberian Express rolled on with a 91-70 victory to remain perfect in Group F of the U20 European Championship Men.
Marc Fernandez had 24 points and Javier Beiran Amigo added 16 as Juan Antonio Orenga's team moved to 3-0 atop their Qualifying Round group.
The Group C winners had a fight in their hands with Bulgaria early as Chavdar Kostov scored Bulgaria's first 14 points and Ivan Chokalov's team led 20-14 before Spain evened things at 25-25 after one period.
Spain opened a 45-39 half-time lead and it was 53-43 until Bulgaria closed to within 60-54 with four minutes left in the third. But Orenga's side scored the final 11 points of the quarter (71-54 after three) and pushed ahead 75-56.
Bulgaria offered their final resistance as Nikolay Kolev hit one three-pointer and Bozhidar Avramov buried back-to-back treys to cut the deficit to 75-65 with six minutes left.
But Xavier Rey converted a three-point play and Fernandez drained a three-pointer to start a 16-5 spurt to finish off the game.
Albert Teruel had 13 points and Sergio Llull and Pau Ribas both added 12 points for Spain, who play Georgia on Wednesday.
Kostov had 20 points and Kolev added 14 to lead the way for Bulgaria, who dropped to 0-3 and next face Croatia.