Huesca made its Spanish league debut in style on Sunday, winning 2-1 at Eibar.
The small club from northeastern Spain needed only five minutes to score its first-ever goal in the top flight, coming from Alex Gallar after a neat run through the Eibar defense.
The midfielder also netted the second, a free-kick cross that missed everyone inside the area and went directly into the goal.
Gonzalo Escalante pulled the hosts closer in the 69th.
Huesca had played a total of only eight seasons in the second division before earning its promotion with a second-place finish last season.
The other promoted clubs this season are Valladolid and Rayo Vallecano.
Valladolid opened with a 0-0 draw at Girona on Friday, while Rayo Vallecano plays Sevilla later Sunday when Real Madrid hosts Getafe.