Mikel Merino bagged a goal and Martin Zubimendi produced an assist as Spain got their World Cup qualifying campaign off to the perfect start with a 3-0 win in Bulgaria.
In a dominant first half, Zubimendi helped get the scoring underway, setting up Mikel Oyarzabal with a fine through ball. Chelsea's Marc Cucurella doubled the lead before Merino's header made it 3-0 before half-time - his fifth goal for his country.
Spain head to Turkey for their second group stage match, with both sides on three points apiece.
Elsewhere in Europe, Leandro Trossard came off the bench in a 6-0 victory over Liechtenstein.