Nigeria scored five goals for the second match in a row at the Under-20 World Cup in Colombia as they beat Croatia 5-2 on Wednesday.
The result means the Flying Eagles are the first African side to guarantee a spot in the last 16 of the tournament.
Olarenwaju Kayode and Terna Suswan scored in the first half for Nigeria before Ahmed Musa and two from Uche Nwofor completed the rout.
Ivan Lendric and Andrej Kramaric scored for Croatia either side of half-time.
Nigeria coach John Obuh said that the scoreline did not reflect what happened on the pitch.
"We expected them to be a good team and they showed a good display," he said.
"The game today was tough but luckily for us we managed to win.
"We should carry on scoring goals as long as the opportunity is there to score, (and) we should score as we did in the first two matches.
"We have come a long way to build the team and the players have been together for a long time."
Croatia coach Ivan Grnja admitted his side had been beaten by a better side.
"Today we found an opponent with good quality and we couldn't compete with their quality," he said.
"Nigeria showed that they are strong and they have good players.
"The problem was the physical status of our players - most of the players couldn't compete in the game and that's why we conceded quick goals towards the end of the match.
"We made several mistakes which affected us and allowed Nigeria to score five goals."
In the other Group D game, Saudi Arabia thrashed Guatemala 6-0.
Nigeria's final group game is against Saudi Arabia on Saturday and will decide who wins the group - both sides are on six points but the Flying Eagles have scored more goals.