A Thomas Mueller's hat-trick inspired Germany to a 4-0 win over 10-man Portugal in their opening World Cup Group G match on Monday.

The win in Salvador capped their 100th World Cup match as Germany became the first team to reach the milestone.

Two Mueller goals and a thumping Mats Hummels header blew away a Portugal who saw red in the 37th minute as defender Pepe was dismissed.

Mueller completed the first hat-trick of the tournament after 78 minutes, prodding home a spilled Andre Schuerrle cross.

Germany jump into the lead with games against Ghana and the U.S to come. Both side battle in the other group match in Natal.