Belgium coach Marc Wilmots hailed the performance of Divock Origi after the striker scored a late winner in the 1-0 victory over Russia.
The Red Devils had to rely on a first international goal from the 19-year-old to settle a tight and often dreary contest against Fabio Capello's men.
Origi, who came on in the second half for Romelu Lukaku, found the back of the net in the 88th minute, and Wilmots was thrilled with the display of a player who is only in Brazil due to the injury of Christian Benteke.
"You can see his qualities and he has integrated into the team. He has good technical abilities, is quick, and was very good today," Wilmots told his postmatch news conference.
"Without Benteke's injury, Divock would not be here, so you have to put things in context. I wanted somebody who is disciplined and fast."
Wilmots added on Origi's introduction: "There are two ways of being a substitute. You may be frustrated or you may feel good about it and you want to make the difference. It's the second thing that matters for us.
"I had other people who could have come in, but I wanted to win the match and saw it was a physical match. It was not the best football on earth, but everybody was committed. This is a major asset."
Eden Hazard played a major role in creating Belgium's winner, but Wilmots feels the best is still to come in the World Cup from the Chelsea player.
"There are some details that can be corrected, but I know he's very good, one-on-one in particular. He dribbles very well and looks for spaces. You have to be patient," he said.
"We know how good Eden is. From a tactical point of view, he knows exactly what I expect from him. We talk about things and try to make headway."
Hazard himself was pleased to see his side gain all three points to secure qualification for the next round, while he is predicting another win for Belgium when they take on South Korea in their final game.
"It was a complicated match. We're happy with the victory because we have one match to go and have already qualified. We will try to get three wins in this qualifying campaign," he said.
"We didn't play a very good match. The last ten minutes were good. The Russian defence was a bit tired, so we had more space to work in.
"Lukaku didn't possess the ball much and didn't have much space. Divock took advantage of the situation at the end of the match, but both had an influence in the victory."
Wilmots added on Belgium's progress to the round of 16: "This is the second-youngest team in the World Cup, but we are mature. I tell my players not to be nervous. You have to be very effective in a World Cup and what is important is that we have been able to qualify for the knockout stage."