Express Diallo hauls Strasbourg away from trouble
Diallo took his goals tally to 20 for the season and secured a fourth victory in five matches for Strasbourg which lifted them six points clear of the relegation zone.
Over two-thirds of his goals have come since January, when Strasbourg were second from bottom having won just once in 18 games.
His first against Nice came after 40 seconds as he controlled Ibrahima Sissoko's long ball over the defence and steered past Kasper Schmeichel.
Diallo added a second from the penalty spot on the hour after Jean-Ricner Bellegarde was brought down in the area by Jordan Lotomba.
He is the first Strasbourg player to reach 20 goals in a top-flight season since 1977-78.
Lionel Messi will start for Paris Saint-Germain in their game at home to Ajaccio later on Saturday following his return from a club suspension for an unauthorised trip to Saudi Arabia.
The Argentine is set to leave PSG in the summer, with the seven-time Ballon d'Or winner said to have agreed a blockbuster deal to play in Saudi Arabia next season.
He will likely make his penultimate appearance at the Parc des Princes as PSG target a record 11th French league title.
Christophe Galtier's side are three points clear at the top after second-placed Lens came from a goal down with 10 men to beat Reims 2-1 on Friday.