Substitute Abdelhamid Sabiri broke the deadlock on Sunday when he outsmarted Belgium goalkeeper Thibaut Courtois by whipping in a free kick from a tight angle at the near post in the 73rd minute.

Belgium and Courtois could not say they hadn't been warned: just before halftime, Morocco had a very similar free kick, taken by Hakim Ziyech, ruled out.

Romain Saiss was marginally offside and referee Carlos Ramos ruled the goal out after a VAR review as the Besiktas defender was obstructing Courtois' view.

When Sabiri struck, Saiss was again the man running across the near post, but this time he was onside.

Zakaria Aboukhlal then guided a shot into the roof of the net from a pass by Ziyech in stoppage time, to the delight of the deafening support for Morocco at Al Thumama Stadium.

Morocco even had to cope with losing goalkeeper Yassine Bounou between the singing of the national anthem and kick off.

Bounou said he was feeling dizzy and was seen in a lengthy discussion with referee Cesar Ramos of Mexico, before being replaced by Munir El Kajoui.

In Brussels, police had to seal off parts of the city centre, and deployed water cannons and fired tear gas to disperse crowds after Belgium's defeat. Dozens of rioters pelted cars with bricks, police said.

This was Morocco's first win at a World Cup since 1998 and only the third in their history.

The victory was a triumph for coach Walid Regragui. Since he took over in September, Morocco have kept clean sheets in six successive matches.

"Today we have achieved nothing. I know everyone is delighted but I know football and you need to respect the game," Regragui said.

"I want everybody to be happy now but we need to recover quickly and get back to work. Canada will be a hard team to play and we have to respect them.

"We have to keep fighting, we want to get past this round and go to the next level."

Regragui was effusive in his praise for his squad.

"We played against one of the best teams in the world with big players, but we know that if you don't give 100 per cent, it is impossible to win. With these players and these fans, anything is possible."

Belgium, ranked second in the world behind Brazil, had won their last seven group games at the World Cup.

They would have become the second team after defending champions France to qualify for the knockout stage if it had beaten the Moroccans but now will play 2018 finalist Croatia in what will be a crucial final group game.

Coach Roberto Martinez put on star striker Romelu Lukaku, the country's record scorer, as a substitute with less than 10 minutes to go in a desperate attempt to get one back.

Lukaku hadn't played since October and is only just returning from a left thigh problem. He struggled to make an impression as Morocco threatened on the break before Aboukhlal's clinching second goal.

Belgium reached the semifinals at the 2018 World Cup in Russia, before losing to eventual champions France.

But they laboured to a 1-0 win over Canada in their opening game, when the absence of Lukaku was glaring.

"It is a difficult result because the first goal affected a lot the outcome," Martinez said. "It was a dead-ball situation and from that point we couldn't get our game going.

"I think we had good moments but we couldn't get clear chances."

with agencies

Australian Associated Press