Diego Costa's long wait for an international goal ended when the Brazil-born forward netted the third goal in an uninspiring 4-0 win for Spain away to minnows Luxembourg in Euro 2016 qualifying Group C on Sunday.

Costa had failed to find the net for his adopted country in six previous appearances but broke a duck lasting more than 500 minutes when he struck from close range in the 69th minute in a rain-lashed Luxembourg City.

David Silva opened the scoring in the 27th minute with a fine long-range drive and set up Paco Alcacer to make it 2-0 three minutes before halftime before substitute Juan Bernat added the fourth two minutes from the end.

The European champions, facing a team ranked 127th in the world, hardly dispelled doubts about their form following Thursday's surprise 2-1 loss in Slovakia, their first defeat in a qualifier for a major tournament in eight years.

However, the easy win put them back on track to qualify from a pool that also includes Ukraine, Belarus and Macedonia.

"It was really annoying me not being able to score but now I can turn the page and hopefully things will go well for me," Costa said in an interview with Spanish television.

"It was getting to me a lot and all the more so when we lost games, I was hurting," added the 26-year-old, who has been in prolific form for his new club Chelsea.

"The coach did nothing else apart from support me and he gave me a fresh chance each match to show what I can do."

Slovakia top the group on nine points after they won 3-1 in Belarus. Spain and Ukraine each have six points, with Macedonia on three and Belarus and Luxembourg on one each.

Patient start

Spain coach Vicente del Bosque made four changes, with David De Gea replacing decorated captain Iker Casillas in goal the most eye-catching.

Casillas, a fixture for Spain for more than a decade, committed another blunder against Slovakia and there were widespread calls for De Gea to be given a chance to show he can reproduce his fine form for Manchester United.

De Gea had little to do as Spain controlled possession for long periods but looked solid when called into action.

Alcacer joined Costa in attack with Cesc Fabregas relegated to the bench and Dani Carvajal and Marc Bartra were deployed in defence in place of Juanfran and Raul Albiol.

After a patient start when Costa and Alcacer both went close, Silva made the breakthrough when he controlled a bouncing ball just outside the penalty area and lashed a rising shot into the top corner.

Costa sliced an effort wide when through on goal four minutes later before Alcacer made it 2-0 when he controlled Silva's neat layoff and hooked a shot into the corner.

It was the Valencia striker's third goal in four appearances for La Roja and Bernat added a fourth when he ran on to a pass from fellow substitute Rodrigo and slipped the ball past Luxembourg goalkeeper Jonathan Joubert.

Spain's next outing is against Belarus in Huelva on Nov. 15.