In the semifinals, he beat William Saidi by first-round knockout, and won the tournament with a decision win against Vang Moua.
[4] Following a successful title defense against Antoine Habash at World GBC Tour 8, Nait Slimani took part in the 2015 Simply The Boxe four man tournament.
Nait Slimani was then scheduled to fight Antonio Campoy at Battle of Saint-Raphael 3 for the WKN International -66.7 kg title.
[6] Nait Slimani participated in his second World GBC Tour four man tournament, and faced Cosmin Podoriu in the semifinal.
[21] During the 2017 Monte-Carlo Fighting Trophy event, Nait Slimani fought a rematch with Antoine Habash, for the WAKO Pro World -64.5 kg title.
[25][26] His six fight winning streak was snapped at Enfusion 60, during which he lost an extra round decision in a rematch with Hamza Essalih.
[27] In November 2018, Slimani fought Daniel Puertas Gallardo for the vacant La Nuit des Champions -65 kg title.
Slimani defended his NDC title for the first time against Sergey Kulyaba in November 2019,[30] and won the fight by split decision.
He made his promotional debut at Superkombat Universe on November 1, 2021, against Mo Monteur for the world super lightweight title.
[40] Slimani was expected to challenge Václav Sivák for the WAKO Pro World K-1 Light Welterweight (-64.5 kg) title at Yangames Fight Night on July 29, 2023.
[42] Slimani rematched Anass Ahmidouch on April 6, 2024, at La Nuit des Gladiateurs 15 for the promotion's -65 kg title.