(CNN) -- Euro 2008 champions Spain took another giant step towards World Cup qualification with a 1-0 home win over Turkey in Madrid.
Pique (center) is congratulated by teammates after his crucial goal in the Bernabeu.
It was their fifth straight victory in Group Five and secured with a goal just after the hour mark in the Bernabeu by Gerard Pique.
The Barcelona defender scored from close range after a free kick deflected into his path.
The 22-year-old Pique, a former Manchester United player, was playing only his second international after making his debut against England.
Spain, who top the FIFA world rankings, have a perfect 15 points in the group, with Bosnia, 4-2 winners in Belgium earlier on Saturday, in second place but six points adrift.
Bosnia's game in Genk was marred by an incident in which a smoke bomb was thrown on the pitch by visiting fans.
Edin Dzeko gave Bosnia an early lead before Moussa Dembele equalized midway through the second half.
However, the visitors hit back with three goals in 12 minutes through Sanel Jahic, Zlatan Bajramovic and Zvjezdan Misimovic. Wesley Sonck's late penalty was mere consolation for the home side.
Turkey, who entertain Spain in a return match in Istanbul on Wednesday, are in third place on eight points with Belgium in fourth.
Turkey, who reached the semifinal of Euro 2008, started brightly against the in-form Spaniards with home keeper Iker Casillas called into action early.
David Villa and strike partner Fernando Torres both had half chances until Pique popped up to score on the home ground of Barca's great rivals Real Madrid.
Spain are unbeaten in 30 games dating back to November 2006 and one of the favorites for the World Cup finals in South Africa next year with qualification all but secured.