a tour de force
tour de force
An exceptionally masterful performance or achievement, especially in the arts. The director's latest movie is a tour de force of filmmaking. The Olympic gymnast's final routine was a tour de force that earned her a gold medal.
a tour de ˈforce(from French) an extremely skilful performance or achievement: a literary/cinematic tour de force
This is a French phrase that means ‘an act of strength’.