The 23-year-old former Belgian junior track champion prevailed at the end of a 149.2km stage from Bitam in Gabon to Ebolowa in Cameroon in a bunch sprint.
He beat Europcar's Yohann Gene and Andrea Palini of Lampre-Merida to the line. Massimo Graziato (Lampre) and Adrien Petit (Cofidis) completed the top five.
The eighth edition of Africa's only 2.1 rated race by the UCI sees nine African national teams join UCI ProTeams Lampre-Merida and Lotto-Belisol plus Europcar, Cofidis, Groupement Sportif Oil and MTN-Qhubeka in the seven-day race.
The stage was animated by seven leaders who got a maximum gap of 7:30 before but with 20km remaining it was Azzedine Lagab (Groupement Sportif Oil) out in front alone.
But he was reeled in with 3km remaining and it was Robert who claimed his first professional victory.
He said: “My goal was to win a stage and when you succeed in the first stage, a cyclist can’t be anything but happy. Before the stage the plan was to bring me in position for the sprint. The whole team gave everything they had to catch the last escapee and I had asked Vicente Reynes to keep me in the wheel of Yohann Gène, which he did. I immediately felt that I was very strong and I could easily get out of his wheel."