Evaristo was not the first to announce to General Liniers the evasion of the English vanguard. Colonel Lopez had also watched them all the morning, hovering on their flanks and rear, but not venturing to molest them. When he saw them march from their second position straight for the Paso Chico, he sent off an officer at once to the general with the intelligence, and putting himself at the head of such of his cavalry as he could collect around him he drew them up across the road leading to the pass. One British regiment deployed, poured in a volley, charged, and drove most of the horsemen pell-mell across the pass to the other side, dispersing the rest in all directions. Again collecting some of his scattered troops, Colonel Lopez endeavoured to cut off the retreat of the detachment which had remained on the lomada. But the ground favoured the light-armed infantry. Instead of following in the track of the main body, they made at once for a quinta which lay between them and the river, and bursting through the fences, which were impracticable for cavalry, reached the pass, and crossed without the loss of one man. The colonel then led his troopers to the road at a gallop, but on reaching the river was met by a volley of grape from two field-pieces in position on the far bank. Many of his men fell. He drew back to the shelter of the poplars which formed the quinta fence, and awaited the arrival of his nephew.
Marcelino, dismounting when he reached the quinta, led his men on foot to the edge of the river, just in time to witness the repulse of the cavalry. The owner of the quinta had a boat moored to a post about a square down the stream, hidden from sight of the pass by a bend in the river and the trees of another quinta on the left bank. Enjoining the strictest silence, Marcelino marched his men with trailed arms through the quinta to beyond the bend, rapidly passed them across the river, and took possession of the other quinta without being perceived by the enemy, who first knew of his whereabouts as from the shelter of the trees he opened a heavy fire upon the artillerymen and the light infantry who had halted close at hand. Colonel Lopez, who had been informed by him of his intention, and who had meantime been reinforced by several squads of cavalry, once more emerged into the main road, and, at the head of a yelling mob of horsemen, dashed through the pass. For a moment the capture of the guns appeared inevitable; the artillerymen defended themselves desperately, but were completely surrounded by the furious horsemen.