Luke Amos' winner against Derby was his sixth goal of the seasonDerby County have been relegated from the Championship after suffering a dramatic late defeat at Queens Park Rangers.
Luke Amos' 88th-minute winner for QPR, coupled with Reading's remarkable 4-4 draw against Swansea, consigned Wayne Rooney's beleaguered Rams to the drop to League One.
Relegation with three games to go means Derby will play in England's third tier for the first time since 1986.
Their fight for survival, in a campaign crippled by a 21-point deduction, could only have been prolonged if they equalled or bettered Reading's result.
When Amos coolly slipped the ball past goalkeeper Ryan Allsop, their hopes of staying up had taken a major blow but were not over.
However, Tom McIntyre's 95th-minute leveller for the Royals ended what dim hopes the Rams had left.
Even then, Tom Lawrence was sent off for a second yellow card for a foul on Charlie Austin to compound Derby's misery.
QPR ended a seven-match winless run to move up to 10th in the table and to within two points of the top six, although sixth-placed Sheffield United could increase that gap if they beat Bristol City later on Monday.
In a nervy first half of the high-stakes game in west London, Amos had an early goal ruled out for offside while Luke Plange skimmed Derby's best chance off the top off the crossbar with a header.
A crucial block from Derby full-back Nathan Byrne to foil Lyndon Dykes after the half-hour mark summed up the steadfast determination Rooney's Rams have played with throughout a fraught campaign.
If not for the 21-point deduction this season, for entering administration and breaching the EFL's financial regulations, Derby would be 17th in the table and almost as close to the play-off places as the relegation spots.
Allsop made two crucial second-half saves, denying Ilias Chair and Dykes, but Amos finished a quick counter attack with two minutes left to break Derby's resistance and ultimately shatter what hopes they had of avoiding the drop.
Five players with deals for next season & 208 days in administration
Derby's spirited attempt to stay in the Championship is over, but the protracted efforts to sell the club are ongoing.
US businessman Chris Kirchner was confirmed as the preferred bidder to buy the club earlier this month, but while the sale continues it means Derby remain in administration - having been placed there by former owner Mel Morris 208 days ago.
With just five players contracted to the club for next season and the club under a transfer embargo, rebuilding the East Midlands club in League One will present significant challengers for whoever is involved.
Rooney's future with the Rams is also uncertain, with the 36-year-old linked with the vacant job at Premier League side Burnley. Earlier this season he rejected an approach from boyhood club Everton to speak to them about taking charge at Goodison Park.
Line-ups
QPR
Formation 4-2-2-2
29Westwood
22Odubajo28Sanderson20Dunne16McCallum
17Dozzell15Field
8Amos10Chair
14Thomas9Dykes
29Westwood22OdubajoSubstituted forKakayat 58'minutes28Sanderson20Dunne16McCallum17DozzellBooked at 59minsSubstituted forJohansenat 75'minutes15FieldBooked at 72mins8Amos10Chair14ThomasSubstituted forAustinat 71'minutes9DykesSubstitutes
2Kakay7Johansen11Austin12Ball19Gray37Adomah38MahoneyDerby
Formation 4-2-3-1
31Allsop
2Byrne33Davies41Cashin26Buchanan
5Bielik42Thompson
32Ebiowei10Lawrence38Knight
48Plange
31Allsop2Byrne33Davies41Cashin26BuchananSubstituted forCybulskiat 85'minutes5BielikSubstituted forMorrisonat 64'minutes42Thompson32Ebiowei10LawrenceBooked at 90mins38KnightSubstituted forSibleyat 75'minutes48PlangeSubstitutes
3Forsyth11Morrison16Stearman17Sibley21Roos35Watson49CybulskiReferee:Josh SmithAttendance:15,298Live Text
Match ends, Queens Park Rangers 1, Derby County 0.
Second Half ends, Queens Park Rangers 1, Derby County 0.
Second yellow card to Tom Lawrence (Derby County) for a bad foul.
Foul by Tom Lawrence (Derby County).
Charlie Austin (Queens Park Rangers) wins a free kick on the left wing.
Attempt saved. Bartosz Cybulski (Derby County) right footed shot from very close range is saved in the centre of the goal. Assisted by Malcolm Ebiowei with a cross.
Malcolm Ebiowei (Derby County) wins a free kick on the right wing.
Foul by Sam McCallum (Queens Park Rangers).
Goal! Queens Park Rangers 1, Derby County 0. Luke Amos (Queens Park Rangers) right footed shot from the centre of the box to the bottom right corner. Assisted by Lyndon Dykes.
Attempt blocked. Charlie Austin (Queens Park Rangers) right footed shot from outside the box is blocked.
Corner, Queens Park Rangers. Conceded by Curtis Davies.
Malcolm Ebiowei (Derby County) wins a free kick in the defensive half.
Foul by Sam McCallum (Queens Park Rangers).
Substitution, Derby County. Bartosz Cybulski replaces Lee Buchanan.
Attempt blocked. Malcolm Ebiowei (Derby County) left footed shot from the right side of the box is blocked. Assisted by Tom Lawrence.
Ravel Morrison (Derby County) wins a free kick in the attacking half.
Foul by Sam Field (Queens Park Rangers).
Attempt saved. Ilias Chair (Queens Park Rangers) right footed shot from outside the box is saved in the top right corner.
Attempt blocked. Malcolm Ebiowei (Derby County) left footed shot from the right side of the box is blocked. Assisted by Ravel Morrison.
Attempt blocked. Nathan Byrne (Derby County) right footed shot from outside the box is blocked. Assisted by Malcolm Ebiowei.
