Sasson started training in judo when he was eight years old. His coaches are Gill Offer and Oren Smadja, his club is Meitav Jerusalem, and he started competing in 2005. He has worked with Noam Eyal, a sports psychologist who works for the Olympic Committee of Israel. Sasson won the Israeli judo championship at −100 kg in 2007–09 and 2011, and at +100 kg in 2011 and 2012. In July 2009 Sasson won the gold medal at the 2009 Maccabiah Games in Tel Aviv, Israel, in judo at −100 kg. In September 2011 he competed in the Judo World Cup in Tashkent, Uzbekistan, where Iranian Javad Mahjoub was slated to face him, but refused. In February 2012, he won a gold medal in the World Cup Prague in judo at +100 kg. In February 2013 and the following month, Sasson won gold medals in the European OpenTbilisi in Georgia and the European Open Warsaw at −100 kg. In September 2014, he won a gold medal at the European Open Tallinn in Estonia at +100 kg, as he weighed approximately 115 kg and returned from surgery on an injured thumb. On 26 June 2015, representing Israel at the 2015 European Games in judo in the +100 kg category in Baku, Azerbaijan, Sasson won a silver medal for Israel in the inaugural European Games, and in doing so won the silver medal in the 2015 European Judo Championship. He lost to 159 kg Adam Okruashvili of Georgia in the final. He won the silver medal at the 2016 European Judo Championships.
Rio Olympics
At the 2016 Summer Olympics, Sasson defeated Egyptian judoka Islam El Shahaby in the first round. When the match ended, Sasson tried to shake his opponent's hand, but El Shahaby refused—to loud boos and jeers from the near-capacity crowd for the Egyptian's behavior. El Shahaby later announced that he was retiring from judo. Sasson also beat Polish judoka Maciej Sarnacki, defeated Dutch judoka Roy Meyer, and overcame Cuban judoka Alex Garcia Mendoza. His only loss was in the semi-finals against the eventual gold medal winner French judoka Teddy Riner. Sasson was awarded the Olympic bronze medal at Judo +100 kg.
After Rio
Sasson took part in the torch lighting ceremony at the 2017 Maccabiah Games on 6 July 2017. On 8 October 2017, Sasson competed at the 2017 Judo Grand Prix Tashkent, his first competition since the 2016 Olympics, and won the gold medal. On 28 October, he won the bronze medal at the Grand Slam Abu Dhabi after he defeated Benjamin Harmegnies of Belgium by waza-ari. In 2018, he won the silver medal in the 2018 Judo Grand Prix Zagreb. In 2019 he won the gold medal at the 2019 Judo Grand Prix Tel Aviv, the silver medal at the Grand Slam of Ekaterinburg, and the gold medal at the Grand Prix in Budapest.