The former England opener notched 10 fours and four sixes in his 54-ball innings, falling just short of a century in the final over. Ben Duckett supported Hales scoring 52 as the Outlaws posted a huge total of 195 for five from their 20 overs.
Durham made a rapid start in their reply, but once the opening stand between David Bedingham and Graham Clark was broken their chase unravelled. Although Bedingham made 65, the home side fell short and slumped to their first defeat of the season.
Hales said: "It was a really big win for us, these guys have been in good form winning their two previous games.
"This is a tough place to come so to get the win here was very impressive. We batted well, but I thought our bowling was outstanding, defending a total on a small ground with a decent pitch.
"It was difficult to start with on the pitch. Once you got set on the pitch it became easier to score.
"It's something myself and Ben Duckett did tonight. I was pleased we managed to put on that partnership when we were under pressure. Ben Raine bowled two very good balls to stop me getting a hundred I just couldn't get a bat on either of them."
Notts opener Joe Clarke appeared in great touch once again at the crease, striking Matthew Potts for three-straight boundaries. However, Potts responded by finding his outside edge and Ned Eckersley took the catch at the second attempt.
Hales and Ben Duckett upped the ante in response, with the visitors reaching 62 for two at the end of the powerplay. The two players guided the Outlaws beyond the 100-run mark inside the 11th over before putting on the century stand for the third wicket. Hales was the first to fifty from 32 deliveries before Duckett followed one ball later, notching his second half-century in a row in the competition.
Hales then accelerated his innings, clearing the rope twice from one Liam Trevaskis over. Ben Raine broke the 126-run stand for the third wicket, trapping Duckett in front for 52 in the 15th over. Potts produced a piece of brilliance on the rope to dismiss Steven Mullaney, pushing the ball from past the boundary back into the hands of Scott Borthwick.
Late striking from Hales almost guided him to a deserved hundred, but tight bowling from Raine denied the opener and prevented Notts from breaking past the 200-run mark.
Bedingham and Clark began the Durham innings at a rapid rate, smashing the Outlaws opening bowlers around the ground. They reached their fifty partnership inside four overs, handing the hosts a great platform in the powerplay. Clark dispatched Jake Ball over the fence to move to 39, but the bowler made the breakthrough to end the opening stand.
Matthew Carter turned the game on its head by removing Raine and Cameron Bancroft in the space of three deliveries as the home side fell from 73-0 to 77-3. There would be no repeat of Ned Eckersley's Leicestershire heroics for Durham as he fell to Samit Patel, allowing the visitors to take complete control.
Bedingham offered hope by reaching his first T20 fifty of the term, but once he was bowled by Patel the game was up for the hosts, despite a decent late effort from Brydon Carse and Trevaskis.