Zlatko Dalic was left to apologise for Croatia's woeful Euro 2024 showing on Saturday against Spain, whose head coach Luis de la Fuente heaped praise on teenage star Lamine Yamal.

Spain opened a European Championship tournament with a victory by 3+ goals for just a second time, following their 4-1 win against Russia on MD1 at Euro 2008, after a 3-0 triumph against Croatia.

Alvaro Morata, Fabian Ruiz and Dani Carvajal were all on target in a dominant first half, while Bruno Petkovic had a late goal ruled out after his penalty was saved and Ivan Perisic encroached to setup the striker's rebounded finish.

The defeat marked Croatia's joint-heaviest ever defeat at a major international tournament (Euros/World Cup), following 3-0 losses against Portugal at Euro 1996 and Argentina at the 2022 World Cup.

Dalic could only offer his apologies to the travelling Croatia fans after an underwhelming Group B showing in Berlin.

"It was a great atmosphere," the 57-year-old Dalic, who led Croatia to the 2018 World Cup final and semi-finals of the same tournament four years later.

"I apologise for this bad show today. We were not aggressive enough.

"I hope this was just a bad day."

Yet the opening win largely centered around Yamal, who became the youngest player to ever feature at the European Championships after appearing aged just 16 years and 338 days.

The Barcelona winger saw his inviting cross prodded home by Carvajal for La Roja's third goal, much to the delight of Spain boss De La Fuente.

"Yamal is impressing everyone and going up through the levels," De la Fuente said.

"He has to keep improving every day, and over time he will become a wonderful footballer."

De La Fuente also reserved special praise for Fabian, who teed up Morata's opener after 29 minutes.

"[Fabian] is at the top level," he added. "Based on what we see from him on a daily basis, he's fantastic. He has brilliant technique.

"We should recognise the quality that he has. He has real imagination."