Andy Brown scored against his former club as AFC Telford United knocked Nuneaton Town out of the FA Trophy.
Chris Sharp then scored the Bucks' second goal in injury time to secure Sunday's deserved first round victory.
"We were solid and organised," said Bucks boss Andy Sinton. "It was a really professional performance.
"We withstood 15 minutes of territorial advantage, but they never really opened us up and the best chances fell to us," Sinton told BBC Radio Shropshire.
The rivalry between the two Midland clubs is close, especially after Telford's two-leg triumph in last season's Blue Square North play-off semi-finals.
Sean Newton and Phil Trainer both went close before Brown fired Telford ahead on 25 minutes but, as expected, Nuneaton hit back, James Arnison hitting the bar.
Telford twice had the ball in the net, only to be pulled back by the referee.
But Sharp sealed things in injury time, robbing defender Gareth Dean on the halfway line before haring forward to fire clinically past Nuneaton goalkeeper Danny Alcock.
Telford will be away to Cambridge United in the next round.