Born in Montfermeil, Seine-Saint-Denis, Samassa began his career as a youth with local amateur outfit Red Star Paris.
[7] Due to not living up to expectation by some, he was criticized by the local media and supporters alike for his low strike rate, appearing in a total of 32 matches, but scoring only 2 goals.
On 4 August 2009, Marseille announced that Samassa would be loaned out to fellow Ligue 1 club Valenciennes for the entire 2009–10 season.
[11] Samassa waited until May before earning his first call up for joint World Cup-Africa Cup of Nations qualifiers against Ghana and Benin that was played on 7 and 21 June.
Samassa made his debut for Mali in a 2010 World Cup qualifier against Benin, where he scored his side's only goal in a 1–1 draw.
[13] He scored twice during the 2013 African Cup of Nations, with his first goal coming against DR Congo in a crucial 1-1 draw during the group stage.
He then opened the scoreline in the 3-1 third place play-off win against Ghana, which brought Mali bronze medals from the tournament.