The 18-year-old - recalled from a loan at Northern League Division One side Belper - came off the bench seven minutes from time to head home a David Cotterill corner and secure a 1-0 win which dumped out holders Chesterfield at the Keepmoat Stadium.
"It's basic with Jordan right now - he works hard and he scores," Saunders said.
"He's got the right attitude, the work-rate and the basics you need to be a footballer. You either know where the net is or you don't and he headed it in like he's been doing it for years.
"He's scored eight goals in 10 games at Belper which has been great for him and that goal will have done him the world of good. It's great when a substitute comes on and wins a game like that for you. You need a bit of luck as a manager.
"That's probably the best we've played this season. The possession stats must be ridiculous because we had the ball all night."