We have studied the two-dimensional structure of an accretion disk without angular momentum near a black hole using the Grad-Shafranov equation. When the two-dimensional structure of the flow is systematically taken into account, the singularity of the hydrodynamic equations is located at the sonic surface, rather than at a displaced surface, as occurs when the disk thickness is estimated using the standard technique. A transonic flow can also exist for negative energies, which is not possible when the accretion is strictly radial. DOI: 10.1134/S1063772912010015