The guard hand is used to control the attacks

A Boxer's undercut is similar to the "skyward cannon punch" of Shaolin Kungfu. Although many people may not know how to defend against such attacks, it is actually quite easy to counter undercuts if you know how. As an undercut is powerful, it is not advisable to block it. One good counter is to strike the attacking arm. But instead of striking it head-on, it is better to strike it following its momentum.