  The Zeeman effect, which is usually considered to be detrimental to
superconductivity, can surprisingly protect the superconducting states created
by gating a layered transition metal dichalcogenide. This effective Zeeman
field, which is originated from intrinsic spin orbit coupling induced by
breaking in-plane inversion symmetry, can reach nearly a hundred Tesla in
magnitude. It strongly pins the spin orientation of the electrons to the
out-of-plane directions and protects the superconductivity from being destroyed
by an in-plane external magnetic field. In magnetotransport experiments of
ionic-gate MoS$_{2}$ transistors, where gating prepares individual
superconducting state with different carrier doping, we indeed observe a spin-
protected superconductivity by measuring an in-plane critical field
$\textit{B}$$_{c2}$ far beyond the Pauli paramagnetic limit. The
gating-enhanced $\textit{B}$$_{c2}$ is more than an order of magnitude larger
compared to the bulk superconducting phases where the effective Zeeman field is
weakened by interlayer coupling. Our study gives the first experimental
evidence of an Ising superconductor, in which spins of the pairing electrons
are strongly pinned by an effective Zeeman field.
