Abstract. Motivated by a question of Grinblat, we study the minimal number v(n) that satisfies the following. If A 1 , . . . , An are equivalence relations on a set X such that for every i ∈ [n] there are at least v(n) elements whose equivalence classes with respect to A i are nontrivial, then A 1 , . . . , An contain a rainbow matching, i.e. there exist 2n distinct elements x 1 , y 1 , . . . , xn, yn ∈ X with x i ∼ A i y i for each i ∈ [n]. Grinblat asked whether v(n) = 3n − 2 for every n ≥ 4. The best-known upper bound was v(n) ≤ 16n/5 + O(1) due to Nivash and Omri. Transferring the problem into the setting of edge-coloured multigraphs, we affirm Grinblat's question asymptotically, i.e. we show that v(n) = 3n + o(n).