Bhagavatapurana 9.10.5

5. In the course of Visvamitra's sacrifice Maricha and other great Rakshasas were beaten by him, as Lakshmana stood witnessing it.

6. In the midst of all the warriors that had assembled at the court arranged for the Svayamvara of Sita, he (Rama), like a sportful young elephant that breaks a stick of sugarcane, lifted the formidable Siva-given bow brought therein by three hundred men, strung it, drew it and broke it, O king, in the middle.