Slovenia chalked up their first ever WC win when a dreadful mistake by Algeria goalkeeper Faouzi Chaouchi handed them a 1-0 victory in their opening Group C match on Sunday.
Algeria had been reduced to 10 men when Chaouchi fumbled a harmless looking shot from Slovenia captain Robert Koren, allowing the ball to squirt through his arms into the bottom left hand corner of his net.
Six minutes earlier Algeria substitute Abdelkader Ghezzal was sent off for handball having already been booked.
Slovenia's only previous appearance at a WC finals, in 2002, ended in three defeats but Sunday's win has put them top of the group with three points.
“It's going to be more difficult for us now,” said Algeria coach Rabah Saadane. “Our great opportunity was today against Slovenia and we missed that opportunity.”