 Hannibal, with his foragers under attack and his camp in danger of being assaulted, led out a sortie against the attacking Roman infantry.With only a third of the army present and most of their cavalry absent, the outnumbered Carthaginians fought a small-scale battle not of their own choosing, and mostly got the worst of the engagement.The Romans, at first shaken by the initial Carthaginian onslaught, finally gained the upper hand when a fresh force numbering 8,000 foot and 500 horse under Lucius Decimus the Samnite arrived in the rear of the Carthaginians, having been sent by Fabius to join the army at Geronium.