Defeated Egyptian judo fighter Islam El Shehaby was loudly booed when he refused to shake hands with his Israeli rival.
Or Sasson, ranked fifth in the world, defeated El Shehaby in the first round with about a minute and half remaining in the bout.
At the end of the fight the Egyptian refused to shake Sasson's hand, in a major breach of judo etiquette.
Judo players typically bow or shake hands at the beginning and end of a match, as a sign of respect in the Japanese martial art.
When Sasson extended his hand at the end of the bout, El Shehaby backed away during the first round of the judo
The Egyptian refused to take the hand of the Israeli who had defeated him in the first round at the Rio Olympics
When Sasson extended his hand, El Shehaby backed away, shaking his head. The Israeli then walked off in disgust.
The referee called El Shehaby back to the mat and obliged him to bow, and he gave a quick nod of his head.
He refused to comment afterwards.
Prior to the fight, El Shahaby had come under pressure from Islamist-leaning and nationalist voices in Egypt to withdraw entirely.
One angry follower on Twitter said: 'You will shame Islam. If you lose, you will shame an entire nation and yourself.
'We don't want to think what will happen if you lost to an Israeli. Victory will give you nothing. How can you cooperate with a murderous nation?
Mataz Matar, a TV host in Al-Sharq Islamist-leaning network had also urged him to pull out.
He said: 'My son watch out, don't be fooled, or fool yourself thinking you will play with the Israeli athlete to defeat him and make Egypt happy.
'Egypt will cry; Egypt will be sad and you will be seen as a traitor and a normalizer in the eyes of your people.'
Sasson defeated El Shehaby with about a minute and half remaining in the bout
Despite the snub, the International Judo Federation had claimed the fact the fight even went ahead was a major sign of progress.
Spokesman Nicolas Messner said: 'This is already a big improvement that Arabic countries accept to (fight) Israel.'
He added how there was no obligation to shake hands, but to bow is mandatory.
He said El Shehaby's attitude 'will be reviewed after the games to see if any further action should be taken'.
Sasson later defeated Poland's Maciej Sarnacki, qualifying for the quarter finals, where he will face Dutch competitor Roy Meyer.