Catch me if you Cam: Smith wrestles back NSW Open lead

Cameron Smith had an eventful third round at the NSW Open. (Darren England/AAP PHOTOS)

Cameron Smith has shown his class - and a rare display of frustration - while seizing command of the NSW Open with another sublime round on the Murray River.

As his playing partner, LIV Golf teammate and halfway leader Lucas Herbert endured an extraordinary back-nine collapse, Smith surged to a two-shot lead entering Sunday's final round.