Suarez clashed with Chiellini with just over 10 minutes to go at the end of the final Group D clash, in which the winning team was assured of a spot in the last 16.
It was clear immediately that this was more than a normal clash in the box between fierce rivals: Chiellini ran to the referee to show him bite marks on his shoulder, and video replays clearly showed the Uruguayan superstar sinking his teeth into the defender's shoulder.
FIFA are investigating the incident - and Suarez, twice previously banned for biting, looks set to be hit with another lengthy suspension despite escaping punishment during the match.
World Cup rules allow the use of video or "any other evidence" to retrospectively punish players, so there is no question that the 27-year-old is facing a long spell out of the game.
HOW LONG CAN HE BE BANNED FOR?
FIFA's disciplinary code allows for a maximum ban of 24 matches or two years - and they do have the power to impose the sanction on all football, worldwide. The longest suspension FIFA has ever imposed for an offence at a World Cup was eight games for Italy's Mauro Tassotti, who broke the nose of Spain's Luis Enrique with an elbow to the face during the 1994 World Cup.
The Liverpool striker's history of biting means that his ban will certainly be longer than Tassotti's. Suarez was banned for 10 games last year after biting Chelsea's Branislav Ivanovic in a Premier League match and in 2010 he was suspended for seven games for a similar offence against PSV Eindhoven's Otman Bakkal while playing for Ajax in 2010.
It is also not the first time that he has flouted the rules at the World Cup: four years ago he missed Uruguay's World Cup semi-final against Netherlands after being sent off for a deliberate handball on the line that denied Ghana what would have been a match-winning goal in the final minute of extra time.
OUR VIEW 1: The defining moment of the World Cup
Suarez was already assured of a permanent spot in the World Cup hall of shame for his handball against Ghana four years ago; but his latest crime against football has gone far beyond that. What the 'Cannibal of Ajax' did in Natal on Tuesday will become the defining image of the World Cup, just as Harald Schumacher's sickening challenge on Patrick Battiston did in 1982.
The damage to Battiston was far worse - he slipped into a coma, sustained damaged vertebrae and lost several teeth - but at least Schumacher was challenging for a ball.
Suarez's bite is in many ways far more invidious - an off the ball incident that was also an attack on a man whose back was turned.
OUR VIEW 2: How long should Suarez be banned for?
The Eurosport office is split. The most lenient voice said "I don't think biting is that bad", suggesting a 12-match ban covering international games only. Another would like to see a 20-match, worldwide ban. One other said a year ban from all football would be appropriate; two others suggested two years, with Uruguay also being thrown out of the World Cup to ensure that Suarez is punished in the way that will hurt him most - by ensuring that his punishment is shared by all his countrymen.
And one voice suggested that Suarez is an evident danger to others and simply should never be allowed back on a football pitch again. Considering that anybody else biting another human being in the course of their job would be both fired and prosecuted, even that would be fairly lenient on a man already so rich that he never has to work again.
FOOTBALL'S LONGEST BANS
Paolo di Canio: Banned for 11 matches for pushing referee Paul Alcock to the ground during a match between Sheffield Wednesday and Arsenal in 1998.
David Prutton: Banned for 10 matches for pushing referee Alan Wiley after being sent off during a match between Southampton and Arsenal in 2005.
Don Revie: Banned from managing in England for 10 years for negotiating a deal for a new job in the Middle East while still in charge of the national team in 1977. Had the ban thrown out on a technicality.
Vanderlei Luxemburgo: Received a year-long touchline ban while manager of Santos in 2006 for calling the referee gay and saying, "I don't like to be mentally undressed every time the whistle is blown." The ban was cut on appeal to 60 days.
Enoch West: Banned for 30 years for match fixing while playing for Manchester United against Liverpool in 1915. The ban was initially for life, but was lifted in 1945 when he was 59 years old.
WHAT HAPPENS NEXT
FIFA have given Suarez and Uruguay until 9pm UK time on Wednesday to "provide their position and any documentary evidence they deem relevant" to their investigation of the incident. As for Uruguay? They will play Colombia in the last 16 on Saturday night in Rio de Janeiro. Kick-off is 9pm UK time.
WHAT THE MEDIA SAY
"Biting an opponent - just like racially abusing one - is not an acceptable part of the game. For the third time in his career, Suarez will be banned from playing football for sinking his teeth into a fellow professional. Three times: this is not unlucky, this is a pattern of behaviour. This is a pathology." - Jim White, Eurosport blogger, writing in The Telegraph
And in Group E, France will look to continue their highly-impressive start to the World Cup when they take on Ecuador at 9pm, with Honduras kicking off at the same time against Switzerland in the other match.
- Sports & Recreation