A match in the fourth round of La Liga saw Atletico Madrid visit Athletic Club. Atletico had remained unbeaten in their opening three league matches with two wins and one draw. In the first round, Atletico defeated Malaga 2-0. They then continued playing at home and drew 2-2 with Villarreal. After that, Atletico traveled to face Sevilla and won 3-1. This time, Atletico continued their away run against Athletic Club, whose squad had a total market value of only 230 million euros. In the end, Atletico suffered an upset defeat and were beaten by Athletic Club.

Atletico Madrid lined up in a 4-4-2 formation for the match. Lee Kang-in and Baena partnered as the two forwards. Lookman, Hjulmand, Pablo Barrios, and Giuliano Simeone formed the four-man midfield. Grimaldo, Hancko, Marc Pubill, and Marcos Llorente started in the back four. Oblak was the starting goalkeeper. Alvarez, Jonathan David, Koke, and Romero were on the bench waiting for opportunities.

Shortly after the match began, Atletico Madrid almost scored. Lee Kang-in cut past a defender on the right side of the penalty area and fired a low shot toward the far corner. The ball struck the post and rolled past the goal, missing by the smallest margin. In the 18th minute, Sancet's shot inside the penalty area went wide. In the 31st minute, Baena unleashed a powerful shot from the right side of the box, but it was saved. Four minutes later, Lookman curled a shot toward the far corner from the edge of the area, but it went wide. In the 39th minute, Lee Kang-in committed a foul and received a yellow card. In first-half stoppage time, Barrios' shot from a tight angle hit the post and bounced away. At halftime, the score remained 0-0.

The second half began with the teams switching ends. In the 46th minute, Atletico conceded! Inaki delivered a cross from the right side of the penalty area, and Nico Williams arrived in front of goal to head home easily. Atletico's defense had a major lapse, allowing Nico Williams to complete the header comfortably. In the 48th minute, Athletic Club scored again! Inaki Williams played a through ball, Navarro moved forward, beat a defender inside the penalty area, and finished a one-on-one chance with a shot. Athletic Club were extremely sharp. Simeone was stunned as Atletico conceded two goals within two minutes and quickly fell into difficulty.

In the 58th minute, Atletico Madrid made a large number of substitutions, with Arnau Ortiz, Koke, Alvarez, and Romero all coming on from the bench. However, Simeone's changes did not produce an effect. In the 68th minute, Barrios attempted a long-range shot, and the goalkeeper made a diving save. In the 90th minute, Sancet scored with a low shot to seal the victory. Atletico failed to score until the final whistle. In the end, Atletico Madrid lost 0-3 to Athletic Club in an upset result and suffered their first defeat of the new season.