Blackpool 2-1 Derby
Blackpool secured their Championship safety as Ludovic Sylvestre's injury-time winner gave them a home victory against Derby.
Gary Taylor-Fletcher tapped the hosts in front after being set up by Thomas Ince, who later missed a penalty.
The miss looked costly when Derby substitute Ben Davies volleyed a second-half leveller.
But Sylvestre scored with a volley from the edge of the box as his side claimed their third successive home win.
The result takes the Tangerines up to 15th in the Championship and mathematically safe from relegation after a run of only three wins in 13 games had seen them fall down the table.
Derby, who are 13th in the table, had the game's first real chance when Jeff Hendrick drove into the box, only to see his shot blocked by Craig Cathcart.
Taylor-Fletcher then notched his fifth goal of the season, all of them coming at Bloomfield Road, from close range after Ince picked him out.
Blackpool were handed the chance for a second goal when they were awarded a penalty following Craig Bryson's challenge on Kirk Broadfoot.
The Derby midfielder appeared to win the ball, but the Rams will feel justice was served as Ince's spot-kick struck the upright.
The visitors survived another scare in the 50th minute when John Brayford cleared Taylor-Fletcher's shot off the line.
Davies had only been on the pitch three minutes when he levelled for the Rams, volleying home Chris Martin's cross.
Rams keeper Adam Legzdins saved from Nathan Delfouneso with five minutes remaining, before Davies made two clearances off the line that looked like ensuring Derby would earn a point.
But Sylvestre's late volley condemned Nigel Clough's team to a 13th away league defeat this season.
Blackpool manager Paul Ince:
"I'm glad this fantastic club has managed to stay in the Championship and we can go forward next year.
"I'm a bit gutted that it's taken us this long to salvage where we are going to be. You want to be proactive rather than reactive in your planning but we've had to wait until the second-last game to be safe.
"Now I will sit down with the chairman and start getting some targets. We do need fresh faces. I don't want to dismantle the whole team, we have a fantastic core here and spirit, but I just want to add to it."
Derby manager Nigel Clough:
"There was nothing in the game, I thought we edged it second half and we were going to go on and win the game but we end up losing instead of getting a point.
"We thought our performance warranted at least a point. We just vacated the edge of the box in the last few minutes, which we are disappointed with.
"The players are very angry at losing because we hate it, but also they are very angry and upset at the officials' performance - all three of them. You start to doubt a little bit with some of the decisions that were made."