The sell-out crowd witnessed a game with plenty of hard work, fouls and competitivenes, while there was a lack of quality at times.
Ian Harkes came up with the defining moment, turning on the edge of the box to fire past Adam Legzdins. There were some big performances for the Tangeroines, especially in defence and midfielder Jeando Fuchs.
It is the latest big win for Thomas Courts this season after victories over double winners St Johnstone and Scottish champions Rangers.
How did the United players rate out of ten?
Player ratings scale - 10: One of the best performances you've seen. 9: Outstanding. 8: Very good. 7: Good. 6: Average. 5: Poor, 4: Very poor. 3: A terrible day at the office. 2: Abysmal. 1: One of the worst performances you've seen.
13. Louis Appere - 5
PAISLEY, SCOTLAND - SEPTEMBER 11: Dundee Utd's Louis Appere has a shot during a cinch Premiership match between St Mirren and Dundee United at SMISA Stadium on September 11, 2021, in Paisley, Scotland (Photo by Roddy Scott / SNS Group) Photo: Roddy Scott - SNS Group
14. Nicky Clark - n/a
On with nine minutes to go - was involved in build-up to winning goal. Photo: Mark Scates - SNS Group