Middlesex remain on course to lift their first County Championship title since 1993 after a nail-biting five-wicket victory over Nottinghamshire at Trent Bridge.
Set 235 to win and stay in top spot, the Division One leaders were indebted to three solid contributions for getting them to their target during mid-afternoon.
Nick Compton was dismissed in the morning session for 63, but John Simpson and James Franklin saw their side over the finishing line with an unbroken stand of 89.
Simpson was unbeaten on 58, while his captain remained undefeated on 54. Jake Ball took one of the wickets on the final day, giving him figures of four for 54 to complete a nine-wicket haul in the match.
While their success maintains Middlesex’s undefeated record this season, the loss confirms Nottinghamshire’s relegation to the second tier after nine seasons of top flight cricket.
Hopes of an extended stay of execution arose when Ball removed Stevie Eskinazi after an hour of the final morning.
Already spilled at slip by Brendan Taylor, from the bowling of Harry Gurney, Eskinazi advanced his score to 30 before edging behind after Ball had returned for a second burst.
Compton appeared determined and confident as he reached his 50 from 155 balls but he was then involved in an unfortunate breakdown of communications with Simpson, which caused his demise.
After clipping Samit Patel to midwicket, the former England man set off for a sharp single. Halfway down, he had to turn and head back because his partner hadn’t responded.
Jake Libby fielded and threw in to Chris Read, who took the catch above his head and whipped off the bails in enough time to gain the umpire’s verdict.
The dismissal invigorated the home side and their supporters, who burst into life with a forgotten sense of renewed optimism.
That belief was soon diminished as the sixth-wicket partnership blossomed during the opening hour of the afternoon to bring the victory points within range.
Franklin hit Patel down the ground for the only six of the innings, which also took him to a 78-ball half century, soon after Simpson had got there from nine balls more.
Although Middlesex claimed 20 points for the win, their gap over second-placed Yorkshire has been reduced to just one point, with the sides due to meet at Lord’s in the final round of matches in two weeks’ time.
Nottinghamshire’s loss was their eighth of the season and matches the sequence of 2003 when they also went 14 consecutive Championship matches without a win.
Nottinghamshire’s Director of Cricket Mick Newell said: "Financially the drop into Division Two doesn’t make a huge amount of difference to the club but it makes a difference to the supporters. Relegation in cricket is about the shame, it’s about the embarrassment of getting relegated – financially it’s not like losing your place in the Premier League at football.
"We are a proud club, we’ve been in Division One a long time. It’s 10 years since I have stood here to explain away a relegation, so it is more about the impact, the ego if you like, of the players and the impact it has on the supporters."
Middlesex runscorer Compton said: "I always say it, and it’s clichéd, but it is nice to contribute. I was proud of the way I moved and I was proud of the way that I managed to hold things together. I knew that if one of the top three or four could hang around for a while it would get easier, especially if we could build a partnership.
"I think experience gives you that but to have John [Simpson] come in when he did really helped me. I can’t say enough for the way that we are growing as a team."