Belgium head coach Marc Wilmots has warned his side not to lose focus after their 2-0 win over Scotland on Friday.
Goals from Steven Defour and Kevin Mirallas secured a hard-fought three points for the Rode Duivels in their World Cup qualifier at Hampden Park, moving them five points clear of Croatia at the top of Group A.
Belgium can book their place in Brazil if they avoid defeat in Zagreb next week, and Wilmots has urged his players not to rest on their laurels until qualification is mathematically secure.
"In the first half we were sometimes too far from the Scotland goal," he told reporters. "We were not really hurt, but I wanted to see what I had asked for.
"We're not there yet. There's still lots to be done. Let's wait and see in Zagreb. As long as we do not have that ticket in our pocket, we do not go to the World Cup."
Porto midfielder Defour netted the opening goal of the game in Scotland and the 25-year-old believes he is beginning to rediscover his best form.
"We're getting closer. We can't give anything anyway. This is what we've done well in the game today," said Defour.
"I worked very hard for that goal. I have had two difficult years [at Porto] but everything is coming back. That goal was a bonus."