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We report the fastest epithelial contractility observed to date in the primitive invertebrate Trichoplax adhaerens: Single-cell contraction events reduce cells’ apical area by 50% in one second, at least an order of magnitude faster than other examples. Typically, epithelial contractions enable embryonic systems to change shape during development. Their contractility machinery (actomyosin) is working against high load to achieve dramatic tissue deformation. Here we show that the same machinery can achieve the fast contraction we observe in T. adhaerens, in the lack of load. We also show that unique cell and tissue architecture indeed minimizes the load on a contracting cell. Finally, we suggest a physiological role for these contractions: maintaining the integrity of such a minimalistic tissue.