When an opponent tries to grab your legs, you can lock his hands using a Seven-Star Stance

Having learnt to counter a Wrestler's attacks at the final stage, i.e. after he has pinned us down, we proceed to counter at the intermediate stage when he has grabbed our legs, and at the initial stage when he is reaching for our legs. "Fierce Tiger Crouching on Ground" is an excellent counter at the intermediate stage, and "Dragon Dragons Play with Pearl" and "Naughty Monkey Plucks Coconut" are effective at the initial stage. These counters are deadly. Do be careful not to hurt your sparring partner.