Hasdrubal spent the rest of 217 BCE and all of 216 BCE subduing rebellious indigenous Iberian tribes, largely in the south. Under pressure from Carthage to reinforce Hannibal, and having been strongly reinforced, Hasdrubal marched north again in early 215 BCE. Meanwhile, Scipio, who had also been reinforced, and joined by his brother Publius, had crossed the Ebro to besiege the Carthaginian-aligned town of Ibera. Hasdrubal approached and offered battle, which the Scipios accepted. Both armies were of similar sizes, about 25,000 men. When they clashed, the centre of Hasdrubal's army – which consisted of locally recruited Iberians – fled without fighting. The Roman legions pushed through the gap, turned to each side against the remaining Carthaginian infantry and enveloped them. Both sides are reported to have suffered heavy casualties; the Carthaginians' may have been very heavy. The Carthaginian camp was sacked, but Hasdrubal escaped with most of his cavalry.

The Scipio brothers continued with their policy of subjugating the Iberian tribes and raiding Carthaginian possessions. Hasdrubal lost the opportunity to reinforce Hannibal when he was at the peak of his success and an army that was ready to sail to Italy was diverted to Iberia. This effect on potential reinforcements for Hannibal has caused the historian Klaus Zimmermann to state "the Scipios' victory ... may well have been the decisive battle of the war".