The hosts took the lead in the League Two clash after just four minutes when Luke Berry charged down a clearance from Scott Loach which flew into the far corner of the net.
Harrison Dunk then struck the base of the post with a fierce shot moments after the restart, with Zeli Ismail following up and forcing a fine save from Loach as United dominated the early stages.
Mark Cooper's side, however, weathered the storm and were back in the game just before half time, as Haydn Hollis leaped on to Liam Noble’s long set piece delivery in the 39th minute, which was sidefooted against Norris and into the net.
It took the U's just ten second half minutes to restore their advantage when a scramble inside the Notts area from Max Clark’s corner ended with Williamson prodding home from three yards.
From that moment on, the visitors continued to press on and saw not one but two more strikes into the net ruled out by the linesman.
Any hope that Notts had of claiming something from the game went out of the window when Liam Noble lashed out at Darnell Furlong with his right boot to receive a straight red from the referee 11 minutes from time.
Will Notts get any more points this season? Let Pride of Nottingham know your thoughts by signing up to the website, visiting the forum and joining the conversation.