A Bernstein-type result for the minimal surface equation

We prove the following Bernstein-type theorem: if $u$ is an entire solution to the minimal surface equation, such that $N-1$ partial derivatives $\frac{\partial u}{\partial x_j}$ are bounded on one side (not necessarily the same), then $u$ is an affine function. Besides its novelty, our theorem also provides a new, simple and self-contained proof of celebrated results of Moser and of Bombieri-Giusti.