[en] We consider the universal sector of a $d><!--\; >\; -->2$ dimensional large-N strongly interacting holographic CFT on a black hole spacetime background B. When our CFT_d is coupled to dynamical Einstein–Hilbert gravity with Newton constant G _d, the combined system can be shown to satisfy a version of the thermodynamic generalized second law (GSL) at leading order in G _d. The quantity $S_{\mathrm{C}\mathrm{F}\mathrm{T}}+\frac{A(H_{B,\mathrm{p}\mathrm{e}\mathrm{r}\mathrm{t}\mathrm{u}\mathrm{r}\mathrm{b}\mathrm{e}\mathrm{d}})}{4G_d}$ is non-decreasing, where $A(H_{B,\mathrm{p}\mathrm{e}\mathrm{r}\mathrm{t}\mathrm{u}\mathrm{r}\mathrm{b}\mathrm{e}\mathrm{d}})$ is the (time-dependent) area of the new event horizon in the coupled theory. Our S _CFT is the notion of (coarse-grained) CFT entropy outside the black hole given by causal holographic information—a quantity in turn defined in the AdS${}_{d+1}$ dual by the renormalized area $A_{\mathrm{r}\mathrm{e}\mathrm{n}}(H_{\mathrm{b}\mathrm{u}\mathrm{l}\mathrm{k}})$ of a corresponding bulk causal horizon. A corollary is that the fine-grained GSL must hold for finite processes taken as a whole, though local decreases of the fine-grained generalized entropy are not obviously forbidden. Another corollary, given by setting $G_d=0,$ states that no finite process taken as a whole can increase the renormalized free energy $F=E_{\mathrm{o}\mathrm{u}\mathrm{t}}-<!--\; ???\; -->{TS}_{\mathrm{C}\mathrm{F}\mathrm{T}}-<!--\; ???\; -->\mathrm{\Omega <!--\; ??\; -->}J,$ with $T,\mathrm{\Omega <!--\; ??\; -->}$ constants set by $H_B.$ This latter corollary constitutes a 2nd law for appropriate non-compact AdS event horizons. (paper)