He reached another quarterfinal a month later at the Challenger La Manche in Cherbourg, defeating Kenny de Schepper before falling to British Jan Choinski.

At the Open Sopra Steria de Lyon Debru made it to his first Challenger semifinal having defeated former Top 20 Benoit Paire, however he then lost to Alexander Ritschard.

In July, Debru won his maiden Challenger title in Troyes, defeating third seed Timofey Skatov in the final.

The only French players to win at a younger age were Richard Gasquet, Fabrice Santoro, Gael Monfils and Corentin Moutet.

[6] He became the third-youngest Frenchman to win multiple Challenger trophies (since 1978), joining former Top 10 players Richard Gasquet and Gael Monfils.