  As superconductors are thinned down to the 2D limit, their critical
temperature $T_c$ typically decreases. Here we report the opposite behavior, a
substantial enhancement of $T_c$ with decreasing thickness, in 2D crystalline
superconductor 2H-TaS$_2$. Remarkably, in the monolayer limit, $T_c$ increases
to 3.4 K compared to 0.8 K in the bulk. Accompanying this trend in
superconductivity, we observe suppression of the charge-density wave (CDW)
transition with decreasing thickness. To explain these trends, we perform
electronic structure calculations showing that a reduction of the CDW amplitude
results in a substantial increase of the density of states at the Fermi energy,
which contributes to the enhancement of $T_c$. Our results establish ultra-thin
2H-TaS$_2$ as an ideal platform to study the competition between CDW order and
superconductivity.
