NATAL, Brazil — Biting opponents, racist comments — all that looked to be behind Luis Suarez as soccer’s bad boy was maturing into a star.

Then, the old habit that most people leave behind in nursery school cropped up again.

Faced with a smothering and frustrating Italian defense in a must-win World Cup game Tuesday, the Uruguayan superstar responded with his front teeth.

It came about the 80th minute when Suarez and Italian defender Giorgio Chiellini got tangled up in front of the Italy goal. The apparent chomp happened in an instant, but it became a worldwide sensation and could lead to Suarez being kicked out of the World Cup.

The referee didn’t see a bite, and no foul was called despite Chiellini pleading and pulling down his jersey to show a red mark on his shoulder. About a minute later, Uruguay defender Diego Godin scored the winning goal for a 1-0 results that sent Italy, the four-time World Cup champs, home.

Uruguay will continue playing, but FIFA could suspend Suarez, who has twice before been disciplined for biting opponents.

Suarez didn’t confirm or deny the bite but said he was angry that Chiellini — known for his physical play — had hit him in the eye during the game.

“These are things that happen on the pitch, we were both in the area, he thrust his shoulder into me,” Suarez said in Spanish. “These things happen on the pitch, and we don’t have to give them so much (importance).”

Suarez, 27, should be celebrating a career year. After asking to be sold before the season, he stayed with Liverpool, won the scoring title and was named English Premier League’s Player of the Year. Now he’ll try to rehab his reputation all over again.

“I want to say that if he’s attacked, as it has begun in this press conference, we’ll also defend him because this is a football World Cup, not of cheap morality,” Uruguay coach Oscar Tabarez said.

Suarez was suspended following biting incidents in the Netherlands in 2010 and in England in 2013. He also was suspended for racially abusing an opponent. British tabloids have teasingly called him a vampire, and social media artists have had fun manipulating his photo into images of Dracula and Hannibal Lecter.

He was responsible for one of the most talked-about moments of the 2010 World Cup, when he used his hand to prevent a Ghana goal near the end of the quarterfinals. Suarez received a red card and was banned for the next game, but Ghana missed the penalty kick and was eliminated.

Uruguay defender and team captain Diego Lugano suggested Suarez was a victim of his past.

“You need to show me because I didn’t see anything. Did you see it today or did you see what happened in other years?” he said.

FIFA, soccer’s world governing body, can sanction players with bans of up to two years. It had no immediate comment.

Chiellini said Suarez should have been kicked out of the game.

“Not sending off Suarez (was) ridiculous,” Chiellini said. “It was absolutely clear. There’s even a mark.”