  We present full photometric coverage and spectroscopic data for soft GRB
201015A with a redshift z = 0.426. Our data spans a time range of 85 days
following the detection of GRB. These observations revealed an underlying
supernova SN 201015A with a maximum at $8.54 \pm $1.48 days (rest frame) and an
optical peak absolute magnitude $-19.45_{-0.47}^{+0.85}$ mag. The supernova
stands out clearly, since the contribution of the afterglow at this time is not
dominant, which made it possible to determine SN's parameters. A comparison of
these parameters reveals that the SN 201015A is the earliest (the minimum
$T_{max}$) known supernova associated with gamma-ray bursts. Spectroscopic
observations during the supernova decay stage showed broad lines, indicating a
large photospheric velocity, and identified this supernova as a type Ic-BL.
Thus, the SN 201015A associated with the GRB 201015A becomes the 27th SN/GRB
confirmed by both photometric and spectroscopic observations. Using the results
of spectral analysis based on the available data of Fermi-GBM experiment, the
parameters $E_\text{p,i} = 20.0 \pm 8.5$ keV and $E_\text{iso} = (1.1 \pm 0.2)
\times 10^{50}$ erg were obtained. According to the position of the burst on
the $E_\text{p,i}$-$E_\text{iso}$ correlation, GRB 201015A was classified as a
Type II (long) gamma-ray burst, which was also confirmed by the
$T_\text{90,i}$-$EH$ diagram.
