  We present the result of a multi-longitude campaign on the photometric study
of the dwarf nova ASASSN-18fk during its superoutburst in 2018. It was observed
with 18 telescopes at 15 sites during ~70 nights within a three-month interval.
Observations covered the main outburst, six rebrightenings and 50-d decline to
a near-quiescent state. We identify ASASSN-18fk as WZ Sge-type dwarf nova with
multiple rebrightenings and show the evolution of the 0.06-d superhump period
over all stages of the superoutburst. A strong 22-min brightness modulation
that superimposed on superhumps is found during rebrightenings and decline.
Some evidence of this modulation in a form of a sideband signal is detected
during the very onset of the outburst. We interpret the 22-min modulation as a
spin period of the white dwarf and suggest that ASASSN-18fk is a good candidate
for a superhumping intermediate polar.
