Riki missed a penalty but recovered to open the scoring and Nelson Oliveria finished things off as Deportivo La Coruna marked their return to Spain's top flight with a 2-0 win over Osasuna.
Former Real Madrid reserve player Riki, 31, spurned a golden chance when he stepped up from 12 yards on the stroke of the half-time whistle, but responded with the first goal of the game six minutes after the resumption.
Oliveira then wrapped things up with a well-taken second as the Segunda Division champions were able to start with a three-point haul, while Osasuna, who finished seventh last season, were given an early reminder of how hard it will be for them to repeat that.
Substitute Roberto Trashorras' stoppage-time strike saw Rayo Vallecano grab all three points in their 1-0 opener against an unfortunate Granada.
The visitors had the better chances, most notably with Rayo keeper Martinez Ruben pulling off an outstanding save from Fabian Orellana before Guilherme Siqueira's header cannoned off the bar immediately afterwards.
They were made to pay for their profligacy as Trashorras came off the bench to fire a tremendous 25-yard free-kick into the top corner to help Paco Jemez's side off to the ideal start.
In the day's late game, Real Zaragoza fell to a 1-0 defeat against Valladolid thanks to a goal from Oscar Gonzalez on the stroke of half-time.
Valladolid were promoted via the play-offs last season and were forced to wait until the final game of Matchday One to make their mark and it was a special return to his former club for Oscar who netted the only goal in his first game in the division since 2008, when he left Zaragoza for Greek side Olympiakos.
The striker latched onto a pass from Omar Ramos to smash the ball past Zaragoza goalkeeper Roberto Gago and give his side the perfect start to their La Liga campaign.