I will discuss a spherically symmetric gravitating model that exhibits turbulent dynamics, a phenomenon conjectured to be the core mechanism of instability of the anti-de Sitter solution. Using the resonant approximation, I will provide compelling evidence that generic arbitrarily small initial perturbations of amplitude epsilon lead to a black hole formation on the timescale 1/epsilon^2. Additionally, I will argue that the perturbative approximation remains valid until the formation of the apparent horizon.