Burnley moved five points clear of Derby County in the race for automatic promotion from the Championship with a 2-0 win over Steve McClaren's side at Turf Moor.
The game started at a slow pace but Burnley striker Danny Ings nearly brought it to life when he pounced on the ball 20 yards from goal and fired a shot; however, his effort went just wide of the post.
Sean Dyche's team were doing the majority of the pressing and Ings was involved again as he and Sam Vokes nearly combined in the box for a shooting chance, but Jake Buxton was on hand to make an excellent tackle to break up the play.
Burnley finally made their dominance pay when they took the lead in the 29th minute. The Rams gave the ball away from a corner, and Jones powered a volley over Lee Grant and into the net.
Matters got worse for the visitors just before the break when Chris Martin was sent off for a second bookable offence for simulation.
After half time, the Rams came out fighting and substitute Connor Sammon almost got them an equaliser when he fired an effort at goal, which squirmed under Tom Heaton, but he was able to gather before it crossed the line.
McClaren's side continued to press as Jeff Hendrick and Patrick Bamford hit efforts over the bar, but Burnley all but killed the game when they doubled their lead when Marney fired home close range following a scramble in the area.
Sammon again tried to reduce the deficit after he and Bamford linked up, but his drive from the edge of the box went wide of the post, allowing the Clarets to secure the three points.