Here your opponent is stopping the single leg takedown with a strong whizzer. If they are strong or have good base you may be stuck here. The backsweep is a good counter to the whizzer by trapping the opponents whizzering arm and using it to sweep them. Lean into your opponent to cause them to become off balanced. Then use your near arm to reach underneath your opponents legs. Fall to your back shoulder and turn away from your opponent while at the same time lifting with your arm. This will cause your opponent to fall over to their back, allowing you to be on top.