An escapement mechanism of a timepiece, including: a first escapement wheel, a second escapement wheel called an impulse pinion and a drive pinion; the impulse pinion, the drive pinion and the first escapement wheel being mounted on the same axis; an intermediate wheel meshing with the drive pinion; a balance plate carrying a plate peg and a direct impulse pallet stone arranged to cooperate with the first escapement wheel; pallets including a pallet entry cooperating with the plate peg, an impulse pallet stone arranged to cooperate with the impulse pinion, and first and second support pallet stones arranged to cooperate with the first escapement wheel. The first escapement wheel, the drive pinion and the impulse pinion are mounted in this order.