Thus inspired by his conviction, they agreed to follow him and chose him to be their leader. Viriathus had the men line up for battle as if they were intent on fighting the Romans.
With a masterful display of battlefield wit, he chose 1000 of his best men to stay by him and commanded the rest to scatter in different directions and then make their way by varying routes to the city of Tribola the moment he mounted his horse.
Vetilius chose not to pursue the fleeing Lusitanians and instead accepted Viriathus' offer of battle. Over the course of two days, Viriathus and his cavalry harassed the Romans with a strategy that Appian so appropriately called "dashing around on the (same) field"; which must have been a constant ebb and flow of attack then withdrawal in a purposefully confused manor.
During the second night and once Viriathus had supposed that the others were safe on the way to Tribola, he and his cavalry absconded during the night and made their way swiftly for the meeting point. The Romans pursued but according to Appian were not able to follow at an equal pace "by reason of the weight of their armor, their ignorance of the roads, and the inferiority of their horses."
Once reunited with his forces, Viriathus set an ambush for the Romans en route to Tribola. As the Romans passed through, Viriathus' forces attacked them from all possible sides, killing quite a few by driving them over a cliff and taking many others prisoner. According to Appian, Vetilius himself was one of the prisoners but the man who took him prisoner "not knowing who he was, but seeing that he was old and fat, and considering him worthless, killed him."
Scarcely more than half of the Roman forces survived the ambush and those that did, retreated all the way to Mediterranean coast near the Straights of Gibraltar and behind the walls of Carteia. The Quaestor who had accompanied Vetilius fortified Carteia with the survivors and sent for aid to Rome's Celtiberian allies where he received 5000 reinforcements from the Belli and Titthi tribes. He subsequently sent them out to face Viriathus and they were defeated to such an extent that none returned to report on the outcome. With the Quaestor and his forces not risking to venture outside of Carteia, Viriathus and his forces ravaged the allies of Rome in the countryside of Carpetania for the rest of the year.