Seeded fourth in the tournament, the Israeli started as the firm favourite after beating top seed Yibing Wu of China in the semi final.
Oliel slipped behind 0-2 at the start of the match but recovered well to take the first set 6-4.
The second set was also evenly balanced with the Hungarian eventually winning 3-6.
But in the final set Piros was by far the stronger player with Oliel making many unforced errors to lose 2-6.