Spain saw off a dogged Finland side as they kept ahead of rivals France in their quest to the World Cup next summer.
Barcelona left back Jordi Alba put the world and European champions in front in Helsinki after just 19 minutes.
The hosts nearly took the lead themselves moments earlier through Celtic signing Teemu Pukki, but he couldn't beat Iker Casillas.
Spain enjoyed plenty of play in attacking areas but the Finns set out to defend in much the way they frustrated La Roja in their previous meeting when they drew 1-1.
However, Vicente del Bosque's charges were getting more reward for their dominance with David Villa failing to convert a good chance before the half-hour mark.
Spain tried to find a second goal but Alba was denied by keeper Niki Maenpaa and Finland's Teemu Tainio squandered a great opportunity to equalise after 63 minutes.
However, the visitors were able to find a winning goal through Manchester City new boy Alvaro Negredo with four minutes remaining.
The result increases Spain's lead at the top of Group I after France could only draw to Georgia.
Meanwhile, Finland face an almost impossible task to reach the playoffs, trailing Les Bleus by five points with two games remaining.
