Mario Mandzukic's early header proved enough for Croatia to claim their second straight win in World Cup qualifying Group I with a 1-0 triumph over Finland in Helsinki.

Mandzukic headed home from an Andrej Kramaric cross in the 18th minute to get his side, fresh from Thursday night's 6-0 win over Kosovo, off to a good start.

The struggling Finns rarely threatened Danijel Subasic's goal while Croatia came close to adding a second when Ivan Perisic rattled the woodwork midway through the second half.

Home keeper Lucas Hradecky saved well from Mandzukic and Duje Cop as the visitors closed out another three points with relative ease.