Durham 253 and 208 for 2 (Borthwick 117, Jennings 65*) lead Derbyshire 113 (Rushworth 6-64) by 348 runs
Six wickets for Chris Rushworth, who began the match expecting to be a temporary stand-in for Graham Onions, and a century by Scott Borthwick put Durham in a position of total command on the second day of their LV= County Championship match against Derbyshire at Chester-le-Street.
After dismissing Division One's bottom club for 113, Durham reached 208 for 2 in their second innings to lead by 348. Keaton Jennings, who narrowly missed out on a maiden Championship hundred in the first innings, was unbeaten on 65 after sharing a stand of 168 with Borthwick.
This was one of Derbyshire's most pitiful displays of a season which seems certain to end in immediate relegation back to Division Two.
Resuming on 15 for 1, they never recovered from losing lost two wickets in the first eight balls. The Durham seamers produced some excellent swing bowling in the baking heat and the only lengthy resistance came from Shivnarine Chanderpaul, who batted for 103 minutes for 14.
Rushworth swung one in to take out Richard Johnson's off stump in the first over and went on to finish 6 for 64. He is the one player named to stand down if Graham Onions is not required by England at Trent Bridge. It will be intriguing to see if Durham replace him.
Wayne Madsen tried to turn Callum Thorp's second ball of the day to leg and gave the first of four catches to wicketkeeper Phil Mustard. Thorp also had Dan Redfern caught at first slip in recording figures of 11-5-11-2, then Mark Wood struck in his second over when Tom Poynton edged a drive.
Ben Stokes troubled Chanderpaul more than anyone, but it was the irrepressible Rushworth who removed him with the third ball of his second spell. The West Indian made a very late decision to play at it and edged to Mustard.
Two balls later Jon Clare wafted loosely to be caught at gully, completing Rushworth's second five-wicket haul of the season.
Derbyshire were 81 for eight at lunch, needing 23 to avoid the follow-on, and Rushworth had five for 39 at that point. He came under fire for two overs before taking the final wicket when he bowled Mark Footitt for 16.
Mark Stoneman, captaining Durham in the absence of Paul Collingwood with a thumb injury, fell lbw to Tim Groenewald for 10 when shouldering arms.
But Derbyshire began to look demoralised as Borthwick raced to 50 off 48 balls, pulling powerfully as he took advantage of too many short balls.
He reached his 117-ball century with a six pulled over mid-wicket off left-arm spinner David Wainwright, but departed for a career-best 117 when he was lbw on the back foot to the off spin of Redfern.