Durham 245 (Stoneman 96, Anyon 4-87) and 268 for 8 dec (Mustard 73, Anyon 4-79) beat Sussex 112 (Onions 4-50) and 116 (Arshad 3-18, Claydon 3-31, Onions 3-38) by 285 runs
After handsome victories over their closest rivals in consecutive games, who would say that Durham do not deserve to be champions? They are in pole position now, this win taking them 14.5 points clear of Yorkshire at the top of the Division One table with three matches to go.
The race is not done yet. Should Yorkshire bounce back when they test Sussex's fragile confidence at Hove next week and Durham come unstuck in the face of Derbyshire's spirited survival bid, it could all change again. Yet there is something about the skill and enthusiasm propelling this young Durham squad that makes Yorkshire's claim seem less compelling.
Durham had this wrapped up before tea, on the third day no less, as Sussex fell away woefully, lacking self-belief with so many absentees. It will be recorded among Sussex's heaviest defeats after the statistic emerged that their combined total of runs - 228 - was their lowest in a single match since 1926.
That should not take away from Durham's achievement, given that they were not without their own problems, losing Ben Stokes to England and with Callum Thorp, Mark Wood and Jamie Harrison unavailable through injury. Mitch Claydon had to return from Kent, where his loan is now the prelude to a permanent move for next season, to make up the numbers; Usman Arshad, 20, had played only one previous first-class match, although you would never have guessed.
Paul Collingwood, meanwhile, appears to be their ideal captain, with the authority born of his long international career, feeding off their enthusiasm but bringing a calming influence when necessary, ensuring everyone remembers his role. His record since he took the reins from Phil Mustard last year, at a time when relegation looked possible, is 12 wins from 19 matches.
It was his judgment that decided Durham should bat on a little longer in their second innings, even though there were plenty of Sussex doubters who felt he could have comfortably declared mid-afternoon on Wednesday. But having had his fingers burned earlier in the season, when Yorkshire knocked off 335 to win rather comfortably, he was taking no chances. That was his reasoning when he declared 40 minutes into the morning session, just after the lead had passed 400.
Spread over 181 overs, which in theory it might have been, the target almost does not seem that much, although history shows that few teams dismissed so easily in the first innings can shed their cares in the second, at least not to the extent of making 400 to win.
So, more realistically, the game was about Durham taking 10 wickets ahead of a forecast change in the weather. When Graham Onions claimed the first with only his third ball as Luke Wells edged to second slip, it looked unlikely to take long.
Chris Nash and Michael Yardy, the two most experienced batsmen, dug in, as was their duty in the circumstances, and for the next 15 overs, with the ball swinging negligibly under clear skies, Durham could make no further inroads. Then, just before lunch, after conceding nine runs from his first five balls, Claydon came round the wicket to Yardy, who shuffled into the ball, bowled with fuller length, and was leg-before.
Nash departed soon after lunch, again lbw to Claydon, and the next hour and 40 minutes played out in spectacular fashion. Rory Hamilton-Brown, who seemed to push forward ahead of the ball's arrival, edged to Phil Mustard and Claydon had his third wicket, his sixth of the match.
Now Arshad, who had earlier composed an impressive 34, supporting Mustard in adding quick runs, came into his own with the ball, moving one away to have Joe Gatting caught behind, then dismissing Harry Finch and Will Beer with successive balls to be on a hat-trick that saw Steve Magoffin surrounded by Durham fielders.
Magoffin lived to strike a few more blows before falling to Onions, aided by a fine catch by Keaton Jennings at backward point, and the same bowler wrapped things up after Chris Rushworth had removed Ben Brown. Onions claimed seven from a match in which he was not even at his best, after his injury lay-off.
"We had to look over our shoulder in terms of weather and the declaration after what happened earlier in the season because I felt the wicket was flattening out yesterday afternoon," Collingwood said. "I felt I had to get a few more runs on the board just in case the weather did not come tomorrow.
"In the event we had some outstanding performances. For Usman Arshad to come into the side and show the maturity and the skill level he had was fantastic - at times I did not have to captain him. And he looked really good with the bat too.
"And Mitch Claydon to answer the call and make a 600-mile round trip and put his heart and soul into his performance like that - it just shows what spirit there is in that dressing room. He is as pleased as anyone."
Collingwood's responsibility now is to pass on a little more experience as Durham look to stay in front. "I don't think it changes the way we go about our games, the fact that we the leaders now," he said. "We have a good strategy based on four seamers building a lot of pressure and we have shown we can adapt to all conditions and all wickets, not just the ones at the Riverside. I don't think we are going to get scared of the opportunity that we have got."