AFC Wimbledon beat Metropolitan Police 1-0 to clinch the Ryman League Division One championship title.
The Dons had already clinched promotion for the second successive season and will play in the Ryman League Premier Division next season.
Shane Smeltz scored the only goal in the eighth minute to delight a crowd of 3,230 at Kingsmeadow.
The club was founded in 2002 by fans of Wimbledon who were angry at the club's plans to move to Milton Keynes.
They were third in their first season in the Combined Counties League before winning the title 12 months later.
Earlier this season they set a new English senior record for consecutive unbeaten League games when a 1-1 draw with Bromley extended their run to 76 matches.