Sevilla missed the chance to claim a share of third place in the Primera Division as they were beaten in Galicia tonight.
Iago Aspas' penalty on the hour and Enrique de Lucas' 85th-minute clincher did the job at Balaidos.
Paco Herrera's side move into the top half as a result of the win, and few could take issue with their performance as they dominated throughout.
The goals of Alvaro Negredo have been crucial to Sevilla's start to the season, and Celta did well to keep him away from the action for most of the night.
He did serve early warning with a sixth-minute riser, but Celta came into the game after that and Gustavo Cabral should have done better with a close-range header.
Baba Diawara and Park Chu-young then traded efforts, with Park drawing a save out of Sevilla goalkeeper Andres Palop, before Alex Gomez whistled a 25-yarder just wide of his goal.
The same player then had an effort blocked by Alberto Botia, and the home side's pressure continued after the break as Aspa worked Palop from outside the area.
Their dominance paid off on the hour, too, as Aspas put them ahead from 12 yards after Hedwiges Maduro handled the same player's edge-of-the-box free-kick.
Sevilla realised a response was necessary and Jose Antonio Reyes took aim from 30 yards, while Negredo did the same to no effect.
Manu then forced Sergio Alvarez into his first save of the night with a header and, having rode the storm, Celta killed their opponents off as De Lucas broke on to Augusto Fernandez's pass to finish things off from just inside the area.