Although the club did not win any trophies under his presidency, they remained in the top five of the French Championship standings and regained stability despite a difficult financial period.
He lived with his uncle Jean Paul, by African tradition, in Richard Toll (the sugar bastion of Senegal), then in Mauritania, where he completed his schooling from 6 to 10 years.
One of his colleagues at PTT was Tony Salvatori, several times champion of France and international spearfishing, who helped him become a freelance writer for the newspaper La Marseillaise.
Shortly after, he was hired full time, with his main focus becoming the coverage of news regarding Olympique de Marseille.
However, on 29 June 1988, after 249 issues, Le Sport ceased its daily publications and closed (temporarily) due to lack of readers, prompting Diouf to pursue a different direction in his career.
Subsequent to this setback, Pape Diouf organized jubilees (homage tournaments) for players in Africa, including Roger Milla, Eusébio and Boubacar Sarr.
Later, his clients would include Marcel Desailly, Jean-Michel Ferri, Grégory Coupet, Sylvain Armand, Laurent Robert, Roger Boli, Abedi Pelé, David Sommeil, Marc-Vivien Foé, Frédéric Kanouté, Noureddine Naybet, Didier Drogba, William Gallas and Samir Nasri (since the age of 13).
In 2006, he was at the origin of a controversial decision to field an Marseille B-team against rivals Paris Saint-Germain on the 30th (out of 38) round of the Ligue 1 championship.
This decision incurred wrath of the French public, the Professional Football League and the exclusive broadcaster of the championship, Canal+, but it also allowed him to form a "sacred union" with the Olympian supporters.
During his tenure as president, Marseille experienced a consistent progress in the French hierarchy (fifth in 2005-2006, then second in 2006-2007, third in 2007-2008, and second in 2008–2009), qualifying very regularly for the Champions League.
It is a painful observation, like European and, above all, French society, which excludes ethnic minorities.” Due to repeated absences from the Marseille supervisory board as well as conflicts with the president of this board, Vincent Labrune, Robert Louis-Dreyfus decided to separate from Pape Diouf on 17 June 2009 after more than four years of presidency.
He is generally considered one of the major players in the renewal of Marseille at the end of the 2000s, having brought back and then maintained the club for three years in the Champions League.