A download manger running on a computer system identifies an in-progress download of content by the computer system directly from a content system. The download manager causes the computer system to join a peer-to-peer network in which the content is being shared. The computer system starts to receive data blocks of the content from peer-to-peer network, as it continues the download from the content system. Based on the receipt of the content from the peer-to-peer network and from the content system, the download manager determines whether the computer system should rely primarily on the peer-to-peer network instead of the content system for receiving the content. If a determination is made to rely on the peer-to-peer network instead of the content system, the download manager terminates the download from the content system and continues receiving data blocks of the content from the peer-to-peer network.