La Roja claimed a 5-3 extra-time victory when these sides met in the Round of 16 four years ago, but it enjoyed a far more serene outing this time.

Fabian Ruiz released Alvaro Morata to put them ahead after a quiet start, then some clever footwork led to the midfielder's deflected strike beating Dominik Livakovic three minutes later.

Luis de la Fuente made Yamal the Euros' youngest player at the age of 16 years and 338 days, and he rewarded his coach by assisting Dani Carvajal's third on the stroke of half-time.

Croatia looked a shadow of the team that took bronze at the 2022 FIFA World Cup and saw a potential consolation chalked off late on, Ivan Perisic being punished for encroachment as he teed up Bruno Petkovic on the rebound from the forward's saved penalty.

The opening exchanges were low on excitement as Spain struggled to combine its patient approach play with penetration, but Fabian provided the telling pass after 29 minutes.

The Paris Saint-Germain midfielder split the Croatia centre-backs with an excellent throughball, allowing Morata to race clear and finish left-footed.

Fabian doubled Spain's advantage shortly afterwards. Receiving the ball from Pedri on the edge of the box, he turned Luka Modric before seeing his low drive take a slight deflection on its way into the bottom-right corner.

Croatia sought a response as Unai Simon denied Marcelo Brozovic and Josko Gvardiol volleyed wide, but its troubles deepened in first-half stoppage-time, Carvajal pouncing to prod Yamal's inviting cross home.

Yamal could have had a goal to go with his assist seven minutes after the break, but Livakovic made a stunning save to keep his left-footed strike out.

Marc Cucurella made a brave last-ditch block to keep out Josip Stanisic's shot, and Croatia was denied a consolation in bizarre circumstances with 10 minutes remaining.

Simon's mistake led to Rodri pushing Petkovic over in front of a gaping goal, and though the Croatia substitute saw his spot-kick saved, he tapped home Perisic's left-sided cross on the rebound.

However, a VAR review showed Perisic was encroaching, so Petkovic's late finish was disallowed to cap a miserable start for Croatia.

UEFA Euro 2020 was a tournament to forget for Morata, who scored three goals but missed more big chances (six) than any other player before fluffing his lines from the spot as Spain was beaten on penalties by Italy in the semi-finals.

However, Morata came into this tournament on the back of his joint-most prolific campaign in Europe's top five leagues, netting 15 times for Atletico Madrid in LaLiga, and he carried that form into this Group B opener.

He now has seven goals at the European championships overall (three in 2016, three in 2020, one in 2024), with only Cristiano Ronaldo (14) and Michel Platini (nine) bettering that tally.

Morata is also just the second Spain player to reach double figures for goals at major tournaments, with 10. David Villa, its leading goalscorer at UEFA Euro 2008 and the 2010 FIFA World Cup, netted 13.

As Spain made Yamal the youngest player in European championship history, Croatia skipper Modric, aged 38 years and 280 days, became the oldest outfielder to appear at the tournament since Germany's Lothar Matthaus against Portugal in 2000 (39 years, 91 days).

Far from replicating Toni Kroos's metronomic performance in Germany's 5-1 rout of Scotland in the tournament opener, Modric struggled to get a foothold against Spain's cultured midfield trio and was found wanting as Fabian turned him to score La Roja's second.

Veteran Modric and his team-mates struggled to get close to Yamal over on the Spain right, and it was an experienced Spain campaigner who benefitted from the teenager's creativity.

While Yamal became the youngest player to assist in the history of the tournament, Carvajal became the oldest player to score for Spain at the competition, aged 32 years and 156 days.