Slashed.

Shi Lang had suddenly taken advantage and the spear in his hand was stabbed through the chest of the enemy mecha. He did not wait for the enemy to recover from shock and with a twist he pulled out the weapon quickly. Then he swung it hard and hit directly on the side of the enemy mech. 

This strike left the visual system in a glitchy situation and he dashed forward. The Spear was dropped when he took initiative to charge at the enemy. Then his empty palms clasped around the horns on the enemy mecha skull, and with his complete force, he twisted the head. 

The shocked audience heard a simple, clicking sound, and they became aware that the head of the enemy mecha was disjointed. 

Yes, Shi Lang had directly taken off the head after unlocking the clipping system with such efficiency. He took advantage of his technical knowledge. After so many days in this place, he had come to understand how the other parties manufactured their mechas.