Harry Wilson is on loan at Derby from Liverpool
Harry Wilson's brilliant brace for Derby County condemned Swansea City to a third successive league defeat for the first time since 2009.
However, Frank Lampard's Rams stayed seventh in the table after a third win in five while Graham Potter saw his men drop two places to 13th.
Wales forward Wilson's hit both from outside the box, the second after Oli McBurnie's defensive slip.
A Fikayo Tomori own goal gave the visitors late hope, but it was in vain.
Wilson has now scored four goals in his last three games as part of his successful loan move from Liverpool.
Derby again benefited as Wilson made the most of his chances with a spectacular opener and equally impressive second effort, taking his total for the season to eight.
The hosts could have scored more after the break, but a lack of accuracy and Potter's tactical changes allowed the visitors to gain second-half momentum.
That culminated in Tomori putting the ball into his own net under pressure on the line from Leroy Fer with three minutes remaining.
It made for a tense final few minutes, but the Rams held on to secure a victory that left Swansea eight points off the play-offs and the relegation zone after a third loss in seven days and fourth in their last five games.
Richard Keogh hit the back of the net early on for Derby, but was offside and at the other end Dan James' chip drifted just past Scott Carson's right post.
Wilson put the hosts ahead on the half hour, beating Erwin Mulder with a swerving strike.
He added a second with a low shot 10 minutes later after McBurnie gave up possession and almost got a hat-trick before Potter looked to his bench.
On went Fer and Jefferson Montero as Jay Fulton and Cameron Carter-Vickers made way, prompting a Swans resurgence that was rewarded by Tomori's own goal.
He directed Grimes' corner into the home net as Fer threatened, leaving Derby to rue their missed chances, but ultimately thanking Wilson's earlier eye for goal.
Derby manager Frank Lampard:
"The only thing lacking was a third or fourth goal and when you don't score that you leave yourself open to a nervy end.
"Harry is on good form and two very good strikes, particularly the first one, and in a game like today which is a bit tetchy at the beginning you need a moment of magic and he produced it.
"I liked his all-round performance because your eye can easily be drawn to Harry's strikes but he's a young developing player and I thought his work rate was very good.
"He gets the headlines, deservedly so for the moments of quality we know he can produce but he still needs to work off the ball - he did do that today - and he picked up nice positions where he could get the ball and turn."
Swansea City manager Graham Potter:
"No one likes to lose football matches and it's been a bad week for us in terms of results, there's no getting away from that.
"We're disappointed. We knew it was going to be a tough week, we learned a bit again and of course we have to try to turn that learning into better performances and results.
"If you look at the average age of the starting 11, it was young. But the character amongst the players and the willingness not to give up was there again and that's something we have to carry forward."
