Ihave also witnessed a player reacting to his opponent蒺s intentional and illegal blocking by deliberately hitting him with the ball as hard as he could during the course of play.
分析主干：I have witnessed a player reacting
reacting 在句中是现在分词，作宾语a player 的补语;by... hitting...是reacting 的方式状语，hitting 作介词by 的宾语。as hard as he could 是比较结构，表示 尽力 。
译文：还有一次我看到过一个球员在比赛中因为对方的一个有意犯规阻挡，而故意使足了力气把球砸向对方。