We demonstrated active phase locking a nine-element $1.14\mathrm{kW}$ all-fiber master-oscillator power amplifier (MOPA) array using the stochastic parallel gradient descent (SPGD) blind optimization algorithm. Two spectrally combined single-frequency seed lasers, which provide potential ability to suppress the stimulated Brillouin scattering effect, are employed as a master oscillator for the nine MOPA channels. The nine laser beams are tiled side by side into a $3\times 3$ laser array with a fill factor of 40% in the near field. When the SPGD controller is enabled, the metric function is increased 4.1 times, and a visibility more than 90% of the interference pattern at the receiving plane is obtained. The computed phase residual error is less than $\lambda /15$ , despite the phase fluctuation of each channel.