Spain thrashed Costa Rica 7-0 in their first World Cup game since 2006, giving coach Luis Enrique the perfect start to a difficult-looking Group E.
Spain opened the floodgates of goals with Dani Olmo, finishing a move started by Pedri and scoring the country's 100th World Cup goal.
Enrique's men applied constant pressure on Los Ticos' penalty area, and Asensio slotted past a helpless Keylor Navas before Ferran Torres tucked away his penalty, capping off an astonishingly dominant first half.
Persistent second-half pressure paid off once more, as Torres added to the Central Americans' woes by grabbing his brace from six yards out after box chaos.
With 20 of his 26-man squad making their first World Cup appearances, Enrique may have seen this tournament as a chance to usher in a new era of Spanish football, and as Gavi made it five with a sumptuous volley, you could sense Spanish belief reverberating across the stands. The Barcelona youngster was not overshadowed by his midfield teammate Pedri's excellent performance, as he became the tournament's youngest goalscorer since Pele in 1958.
Substitutes Carlos Soler and lvaro Morata capped an excellent performance with a pair of composed finishes in a torturous eight minutes of added time for the powerless Los Ticos, extending their World Cup winless streak to seven.
Earlier, Japan stunned Germany with a 2-1 win in Group E. Japan scored two late goals to come from behind and stun Germany in their World Cup Group E opener on Wednesday.
Midfielder Ilkay Gundogan scored a penalty for Germany on 33 minutes at the Khalifa International Stadium in Doha, and forward Kai Havertz had the ball in the net just before halftime but the goal was ruled out for offside.
However, Japan responded in the final 15 minutes with goals from striker Ritsu Doan and Takuma Asano to claim their first ever win over Germany and cause an early tournament upset.
The shocking outcome was a repeat of their 2018 World Cup nightmare, when they lost their opener to Mexico and were condemned to a group-stage exit after another defeat by South Korea.
Germany's players covered their mouths in their pre-match team photo, while the country's interior minister, Nancy Faeser, sat next to FIFA president Gianni Infantino, wearing the "OneLove" armband, as FIFA's threat of sanctions over protests continued.
Hansi Flick's team dominated early on and were rewarded when Joshua Kimmich found David Raum in acres of space in the box and goalkeeper Shuichi Gonda clumsily brought him down as he turned, with Gundogan converting the penalty in the 33rd minute.
The pattern continued in the second half, with Jamal Musiala shooting over after a penetrating run and Gundogan clipping a post.
