It took Spain just two minutes to open the scoring against England last time out, and they repeated that feat here with another fast start. This time, incisive attacking play cut through the visitors, with the ball eventually worked to Lamine Yamal, who swept in a first-time shot with clinical precision.
Alex Baena made an impact off the bench on Saturday, and he was almost on the scoresheet here as his low strike was parried away by Dominik Livakovic moments later.
Croatia took their time to settle, and they could have been further behind when Pau Cubarsi sent a rifled effort marginally wide, but against the run of play, Vatreni were level before the half-hour mark.
Earning only his third cap for Croatia, Dion Beljo marked the occasion with his first international goal, getting ahead of Dean Huijsen to nod home Ivan Perisic’s inviting ball.
But parity lasted just three minutes, as the world champions responded with a header of their own when Marc Pubill's well-timed run was found by Lamine following a corner-kick routine.
And Spain could have gone into half-time with a two-goal lead, but Mikel Oyarzabal was unable to stay onside to tuck in a rebound before Fermin Lopez struck the post with a bending effort, denying him a first goal for La Roja.
Given that seven of Croatia’s last eight defeats came against sides currently ranked inside FIFA’s top 10, the away side had it all to do in the second period.
That task became even tougher when Pedri threaded a ball through to Lamine Yamal, who controlled it in his stride and whipped an effort in off the near post, taking his Spain tally into double figures.
A Croatian fightback was looking increasingly unlikely as La Roja dominated possession and probed for a fourth, with Livakovic needing to be alert to push Pedri’s strike to safety.
With full-time fast approaching, substitute Nico Williams capped off an excellent Spanish display, jinking into the box and firing home their fourth of the night. Luis de la Fuente has now won each of his last nine games in charge of Spain, with La Roja last tasting defeat on home soil back in 2022 against Switzerland.
Maximum points put the world champions top of their group after two games, three points ahead of their defeated opponents. For Slaven Bilic, it’s a first loss since retaking the reins as Croatia boss, falling some way short of his impressive 14-match unbeaten run the first time around (W12, D2).
Flashscore Man of the Match: Lamine Yamal (Spain)