With a slim but crucial advantage, Leioa left Ibaiondo after defeating Derio in the first leg of the regional final for promotion to Segunda Federación. The team from Sarriena imposed its suffocating pressure on the home team's ball circulation, preventing Derio from feeling comfortable for most of the match.

The match was marked by mutual respect between two teams that know each other well. Derio fielded a lineup with several changes compared to the previous tie, while Leioa repeated its formation, with the only exception being De Eguino replacing the injured Gamiz. The home midfield consisted of Dani Jiménez and Markel Mayo, facing the visitors' high press that hindered Derio's ball movement, often forcing Kevin Ríos to play long balls.

In the first half, Derio had a few approaches, including a shot from Álvaro that went wide. Leioa, for its part, sought to break through on the left wing with Galdos. The game was largely contested in the midfield, with few clear chances for either side, observed by the 1,700 spectators present.

The second half maintained a similar dynamic, although Leioa managed to sustain its strategy of disrupting Derio's build-up play without abandoning attacking intentions. Home goalkeeper Kevin Ríos was key in keeping the score level, notably saving a shot from Oier. However, in the 81st minute, a play by Gayoso down the left resulted in a pass to the center that found substitute Goikoetxea, who, coming from behind, fired a powerful shot past the home keeper to make it 0-1.

Despite Garay having a final opportunity to extend the lead, the score remained unchanged. Leioa now faces the second leg with a minimal but hopeful advantage, while Derio will seek a comeback next Saturday at Sarriena at 7:00 PM.