  A study of transitions between $\Upsilon$ states with the emission of charged
pions using 398 fb$^{-1}$ of data collected with the Belle detector at the KEKB
asymmetric energy $e^+e^-$ collider is presented. A clear peak from the decay
$\Upsilon(1S)\to\mu^+\mu^-$ is observed in the invariant mass distribution of
$(\mu^+ \mu^-)$ pairs from the $(\mu^+ \mu^- \pi^+ \pi^- X)$ event sample. The
mass difference distribution ($M_{\mu^+\mu^-\pi^+\pi^-}-M_{\mu^+\mu^-}$) for
$M_{\mu^+\mu^-}$ from the $\Upsilon(1S)$ mass region has two peaks from
$\Upsilon(2S,3S)\to \Upsilon(1S)\pi^+\pi^-$ decays, with no background. A third
peak at $\Delta M = (1119.0\pm 1.4)$~MeV/$c^2$ can be interpreted as evidence
of a signal from the decay $\Upsilon(4S)\to \Upsilon(1S)\pi^+\pi^-$ with a
subsequent $ \Upsilon(1S) \to \mu^+ \mu^-$ transition. This is the first
example of a non-$B \bar{B}$ decay of the $\Upsilon(4S)$ resonance. The
preliminary estimated branching fraction is equal to
$\mathcal{B}(\Upsilon(4S)\to \Upsilon(1S)\pi^+\pi^-) = (1.1 \pm
0.2(\mathrm{stat.}) \pm 0.4(\mathrm{sys.}))\times 10^{-4}.$
