Belgium have come from behind to beat Algeria 2-1 in their opening match of the World Cup in Belo Horizonte.

Marouane Fellaini and Dries Mertens both came off the bench to score for the Belgians after Sofiane Feghouli had given Algeria a first-half lead.

Both sides started the encounter in cautious fashion, but Algeria came close to making the breakthrough on 17 minutes when Riyad Mahrez sliced his effort high and wide on the angle.

Belgium threatened minutes later when Axel Witsel tried his luck from 20 yards, though his drive parried away by goalkeeper Rais M'Bolhi.

The Belgians struggled to get going for much of the first half, and they were punished on 26 minutes as the Algerians went ahead from the penalty spot.

Jan Vertonghen was adjudged to have dragged Sofiane Feghouli to ground inside the area before the midfielder dusted himself off to slot the resulting penalty past Thibaut Courtois.

Belgium started to look more dangerous after going behind as Witsel and Vertonghen both had chances, but Algeria held firm to maintain their lead.

Another opening fell the way of Nacer Chadli late on in the first half when he was played in on the angle, but the midfielder's scuffed shot was easily held by M'Bolhi.

Despite Belgium being improved at the start of the second period following the introduction of Dries Mertens for the disappointing Chadli, they continued to find it difficult to break the disciplined Algerians down.

Algeria could have doubled their advantage on 54 minutes when Carl Medjani glanced a header wide from a corner, while Vertonghen blasted an effort wildly off target at the other end.

Divock Origi was brought on for Romelu Lukaku midway through the second half, and the substitute should have equalised for Belgium when he was put clean through. However, his tame poke towards goal was kept out by M'Bolhi.

Marouane Fellaini was another substitute deployed by manager Marc Wilmots as time began to run out for Belgium, and the midfielder made his mark with 20 minutes left to play by heading in an equaliser for his side following a cross from the left.

Belgium then turned the game around on 80 minutes as Mertens found space inside the box to drill the ball past M'Bolhi at the near post.

A Fellaini header was saved late on as Belgium looked to increase their lead, while the midfielder could have found the net again before letting the ball get away from him from close range.