Derbyshire will play in the First Division of the County Championship for the first time since 2000 after Glamorgan's defeat of Kent ensured that they and Yorkshire will be promoted regardless of what happens on the final day of the season.
After a delayed finish in Cardiff, as Glamorgan sought the 61 runs they needed to win, Derbyshire had to wait 19 minutes after walking off the field in Derby before they knew their 12-year exile from the top tier was over.
After claiming a first-innings lead of three, and reducing Hampshire to 142 for 6 in their second innings, Derbyshire want to focus on pipping Yorkshire to the title, but captain Wayne Madsen said he would allow his players a modest celebration last night.
"To achieve what we have in a year and a half since Karl Krikken became coach is amazing," Madsen said. "We might have one drink tonight but that will be about it because we really want to win the title having led for much of the season and to do that we will probably have to win this game."
Derbyshire's focus under Krikken has been to promote home-grown talent and it was fitting that Ross Whiteley, one of the four former academy players in the side, was the day's key player, supplementing an unbeaten half-century on his 24th-birthday with two late wickets.
Yorkshire, who began the final round of games one point behind Derbyshire, need eight more wickets to beat Essex in Chelmsford, where Azeem Rafiq added an unbeaten 75 to his first-innings half-century before a declaration at 252 for 8 set Essex 388 to win. Rafiq and Steve Patterson took a wicket each as Essex reached 26 for 2.
Robert Croft took the last Kent wicket in his final match as the visitors, following on, were bowled out for 280. Glamorgan stumbled to 36 for 3 but David Lloyd and Ben Wright saw them home for a win that ensures the Welsh county do not finish bottom.
Somerset are guaranteed the £235,000 runners-up prize in the First Division completing an innings and 148-run win over relegated Worcestershire, who were bowled out for 152 as Pakistan left-arm spinner Abdur Rehman took 5 for 36 for career-best match figures of 14 for 101.
Surrey's troubled former captain, Rory Hamilton-Brown, is to leave The Oval. The 25-year-old, who was granted a prolonged leave of absence following the death of his close friend Tom Maynard in June, has been given permission to talk to other counties after telling Surrey he feels he needs a fresh start.