Belgium beat Iceland 3-1 in an international friendly on Wednesday night, but it was not as straightforward as the scoreline may suggest.
Iceland were coming off a recent victory over Holland, and sit top of their European qualification group with nine points from nine.
They pushed the Belgians hard, and only the goalkeeping of Chelsea's Thibaut Courtois kept the score down.
Tottenham defender Jan Vertonghen described so, after the game, telling HLN: "It was a tough match.
"We gave up too many chances. We were better in the game, but they were always dangerous.
"Courtois is incredible. He saved a lot, which says something about the game. Hopefully Sunday it will be the same score, with slightly fewer opportunities for Wales."
Belgium take on the Welsh in European qualification at the weekend, who have made a strong start to the Euro 2016 group. With Gareth Bale and Aaron Ramsey fully fit, it promises to be a tough contest for Marc Wilmots' side.
The Red Devils scored through Nicolas Lombaerts, Divock Origi and Romelu Lukaku, with Alfred Finnbogason scoring an early equaliser for the visitors.