  It is pointed out that in a wide class of models reminiscent of type-II
Two-Higgs-Doublet Models (2HDM) the signal of the Higgs produced in association
with a top-antitop quark pair ($tth$) and decaying into gauge bosons can be
significantly larger than the Standard Model (SM) prediction without violating
any experimental constraints. The crucial feature of these models is enhanced
(suppressed) Higgs coupling to top (bottom) quarks and existence of light
colored particles that give negative contribution to the effective Higgs
coupling to gluons resulting in the gluon fusion rates in the gauge boson decay
channels close to SM predictions. We demonstrate this mechanism in NMSSM with
light stops and show that $tth$ signal in the $WW$ decay channel can be two
times larger than the SM prediction, as suggested by the excesses observed by
ATLAS and CMS, provided that the Higgs-singlet superpotential coupling
$\lambda\gtrsim0.8$ and the MSSM-like Higgs boson masses are in the range of
160 to 300 GeV.
