SB 10.67.18

taṁ tu saṅkarṣaṇo mūrdhni
 patantam acalo yathā
pratijagrāha balavān
 sunandenāhanac ca tam
Synonyms: 
tam — that (tree trunk); tu — but; saṅkarṣaṇaḥ — Lord Balarāma; mūrdhni — on His head; patantam — falling; acalaḥ — an unmoving mountain; yathā — like; pratijagrāha — took hold of; bala-vān — powerful; sunandena — with Sunanda, His club; ahanat — He struck; ca — and; tam — him, Dvivida.
Translation: 
But Lord Saṅkarṣaṇa remained as motionless as a mountain and simply grabbed the log as it fell upon His head. He then struck Dvivida with His club, named Sunanda.