All the pre-match hype centred around Clough versus Ferguson, scions of two of the most successful managers in the game, each twice winners of the European Cup.
And in arguably their biggest season to date in trying to forge their own reputations in the shadows cast by their fathers' formidable achievements, it was Clough who gained the upper hand courtesy of Gary Teale's scrambled late goal.
Derby, without last season's top scorer Rob Hulse and fellow forwards Giles Barnes and Chris Porter through injury, included summer signings Jake Buxton, Dean Moxey and Lee Croft in their starting line-up.
With Kris Commons and Luke Varney only deemed fit enough for the bench, Steve Davies was utilised as a lone striker.
Peterborough, seeking to create history by achieving three successive promotions, had no such problems in attack. Ferguson opted to field George Boyd, Aaron Mclean and Craig Mackail-Smith, who have scored 102 league goals between them in the last two seasons, from the off.
It looked like it could prove to be a shrewd move on the part of Ferguson junior as his side started brightly, turning the Derby defence at every opportunity. But at the other end of the pitch, Peterborough lacked the early proficiency of their forwards.
Croft's corner was cleared by Mclean but the United defence failed to react to the second cross by Moxey. Buxton headed the ball back across goal where his partner at centre-half Miles Addison stooped bravely to head the ball past Joe Lewis after four minutes.
The goal saw Derby assume control but Clough's side lacked penetration and were restricted to long-range efforts for the remainder of the first-half. Shots from Davies, Teale and Paul Green failed to trouble Lewis.
A 15-yard shot from Mclean that went wide 10 minutes before the break was all Peterborough had to offer in the opening period.
Commons, not fully-fit after only returning from a hamstring injury at the end of July, was called upon at half-time following an injury to Green.
Peterborough responded by introducing Lee Frecklington and Shaun Batt, Keates and debutant Tommy Rowe were the players to make way.
The changes sprung Ferguson's side into life. They suddenly created a host of scoring chances just after the hour mark, but unusually failed to take any of them.
Mclean was thwarted by a last-ditch tackle from Moxey when through on goal before substitute Frecklington shot straight at Stephen Bywater when one-on-one with the Derby keeper. Bywater then produced a superb save to keep out a shot from Boyd and Gabriel Zakuani headed wide.
It looked like Derby had survived Peterborough's onslaught but Bywater's brilliance was undone when he needlessly brought down Batt for a penalty. Boyd coolly stepped up to score from the spot, sending Bywater the wrong way.
However, another goalkeeping howler at the other end spoiled all United's hard work. Lewis flapped at Common's corner and after a scramble inside the six-yard box, Teale poked the ball home.
Commons could have sealed the win in injury-time but after robbing a defender he shot straight at Lewis when one-on-one.