Sandgren just spent 79 minutes to wrap up the week in which he did not drop a single set, reports Xinhua news agency.
"I'm a little lost for words", a relieved Sandgren said when a Norrie service return went over the baseline to end the match.
Sandgren said his extra experience counted.
The American carved out 12 break point opportunities against Norrie's serve and converted four of them, while also sending down seven aces in the final warm-up before the Australian Open, where he reached the quarter-finals a year ago.
The American will drop 360 points on the Monday after the Australian Open ends thanks to his quarter-final result past year.
There, he stole Norrie's serve in game three after a poor forehand from a left-handed Briton who squandered the opportunity to get the break back at 2-3 following a well-constructed attack from Sandgren.
Sandgren had too much power and accuracy for Norrie in the second set, breaking him twice before securing the match. It was his second match win of the day, It was de Minaur's second win of the day, he defeated Gilles Simon 6-3, 6-2 in a rain-delayed semifinal from Friday night. "Today, there were a couple of areas and certain moments that I wasn't quite there".
He saved a break point in the eighth game, eventually clinching the game with his fifth ace, and served out the set in 41 minutes.
"I feel in great form and I'm really proud of myself", she added ahead of making her way to Melbourne for the Australian Open, where she will play Russian qualifier Veronika Kudermetova in round one.