Title holders Italy beat Albania 2-1 after conceding the fastest goal in tournament history while triple winners Spain had no such problems in a 3-0 triumph over Croatia in opening Group B action at Euro 2024 on Saturday.
Albania's Nedim Bajrami fired home 23 seconds into the match, according to the ruling body UEFA, bettering the previous record from Russian Dmitri Kirichenko who struck after 67 seconds against Greece in 2004.
But the Azzurri fought back quickly in Dortmund with goals from Alessandro Bastoni in the 11th and Nicolo Barella five minutes later.
Spain meanwhile scored three times in 18 first-half minutes in Berlin to sink Croatia. Man of the Match Fabian Ruiz set up Alvaro Morata, scored the second himself, and Dani Carvajal wrapped up matters.
Spain's Lamine Yamal became the youngest player in European championship history making his debut at 16 years 338 days, and also provided the assist for Carvajal.
Spain and Italy enter their showdown on Thursday with three points each while Croatia play Albania a day earlier, knowing that the loser faces early elimination.
Italy rebound from early deficit
Italy won the last big event in Germany, the 2006 World Cup, and hope to repeat the feat at the Euros - after failing to qualify for the last two World Cups in 2018 and 2022.
They started in the worst possible fashion when Bajrami pounced on a terrible throw-in from Federico Dimarco and smashed the ball into the roof of Gianluigi Donnarumma's net.
Italy however answered furiously as Bastoni headed the equalizer and his team-mate from Serie A champions Inter Milan Barella drilled home the second five minutes later.
Azzurri almost pay for wastefulness
Italy were in full control now in front of 60,512 fans, with chances including Davide Frattesi hitting the post and Francesco Chiesa aiming just wide.
But they were almost punished for this wastefulness at the death by Albania substitute Rey Manaj whose chip was crucially deflected by Donnarumma.
Coach Spaletti not fully satisfied
"We saw many good things but only partly. It could have gone wrong on several occasions. We were a little sloppy at times," Italy coach Luciano Spaletti said.
Barella added: "Albania played a good match. But we deserved the victory and are savouring it."
Spain are ruthless in Berlin
How good Italy are could be determined in the next game against Spain who started scoring in Berlin's Olympic Stadium - where the final will be played on July 14 - just as Luka Modric's Croatia started to get into the game.
Ruiz's through-ball from the centre circle found Morata on a run and the striker slotted home in the 29th.
La Roja wasted no time to double the lead three minutes later when Ruiz ran past past several defenders before firing home.
Croatia also came close but Spain found the target again two minutes into first-half stoppage time, with Carvajal converting Yamal's cross.
No way back for Croatia and penalty woes
Croatia tried to fight back after the break and had the ball in the back of the net with 10 minutes left after Petkovic had his spot-kick saved by Simon whose fluffed pass had to led the spot kick awarded after Rodri tripped Petkovic.
Petkovic was on target after Ivan Perisic had recovered the ball but the goal was nullified upon a video review because Perisic and several other Croatia players ran into the box before the penalty was taken.
Coach hails 'complete performance'
"This was a complete performance inspired by the competitive genes which run through this team, both the young guys and the experienced once who've won almost everything in football but are still super hungry and committed," Spain coach Luis de la Fuente said.
Morata added: "This is a template for how we have to approach all our matches right from the start."
Croatia coach Zlatko Dalic apologized to the many Croatia fans among the attendance of 68,844, and said: "I hope this was a bad day, a bad reaction. We won't erase everything we've done well, we had good games before."
