Charlie is playing open guard while Tom stands and tries to pass.

Charlie takes his left foot off the hip and uses his leg as a pendulum to help him sit up and hug Tom’s right leg (he keeps his sleeve grip with his right hand).

After sitting up, he feeds the sleeve grip from his right hand to his left hand.

This allows him to post with his right hand and stand up (with Tom’s leg trapped between Charlie’s legs).

Charlie stands up with Tom’s leg trapped.

Charlie lifts the leg and is free to sweep Tom’s other leg.

Charlie finishes the takedown.