In large early cortical lesions, one of the most devastating consequences is the impaired motor dexterity of the contralateral limb. We present the case of an 8-year-old girl with a large left hemispherical porencephaly. Unlike previous reports, the girl exhibited high dexterity of the contralateral hand with preserved independent finger movements. We performed functional MRI of hand motor functions and diffusion tensor imaging, which revealed activation of the ipsilateral motor cortex and absence of a contralateral corticospinal tract. These observations suggest that by intensive training in early life, a complete transhemispheric shift of motor control with high skills can be achieved.