Forest settled instantly - looking every bit a side full of confidence after a run of only one loss in 10 league games.
The imposing figure of Guy Moussi in the centre of midfield was a key man as the visitors controlled the first 25 minutes.
And the electrifying pace of Nathan Tyson, who was preferred to Earnshaw up front, was a constant threat while Marcus Tudgay was also lively as the visitors threatened.
McGugan twice had free-kicks in dangerous positions in the first period: the first a rasping low effort that produced a fine save from Bywater; the second just producing a long shake of the head from his disgruntled manager Billy Davies as it whistled over the bar.
The Reds also had what seemed a decent shout for a penalty ignored when referee Graham Salisbury waved away strong protests after home defender Dean Leacock clumsily challenged Joel Lynch from a corner.
But the best chance before the break undoubtedly fell to the hosts.
Miles Addison outmuscled Wes Morgan and with the Reds appealing for a foul, Addison slid in with keeper Lee Camp and found Chris whose slightly casual finish allowed Luke Chambers to clear the ball off the line.
The chances continued to be in short supply after the interval but it was the hosts who had the upper hand.
He demanded a penalty seconds after the interval after being cleverly chaperoned off the ball at the near post by Lynch and then saw a deflected free-kick drift wide.
By this stage Rams boss Nigel Clough had replaced veteran midfielder Robbie Savage, probably fearing the already-cautioned Welshman would be sent off.
Savage was furious at Clough for being substituted
Savage threw a tantrum, petulantly hurling his boots at the floor in the dugout but the change - James Bailey replacing him - gave Derby greater movement and pace in the middle of the park.
And it was Davies who came closest to finding a winner when his brilliant first-time volley was kept out by Camp.
But just as Derby were getting on top, Forest scored with their first meaningful attempt on goal after the break when Earnshaw fizzed a low shot into the bottom corner from the edge of the box with only 11 minutes left.
Shaun Barker almost salvaged a point with a towering late header but the Reds held on to move into the top six for the first time this season.
Moxey's red card added insult to the hurt pride, but Forest's first win in nine attempts at Derby's home meant that dismissal paled into insignificance as the home fans were forced to watch their rivals lap up the victory on the final whistle.
Derby manager Nigel Clough on his side's seventh defeat in nine games: "It's got to be put into perspective, you can look at the last eight weeks or two years.
"Is there any other Championship club in that time that's brought in more money than it's spent and reduced the wage bill by nearly half? We are still just about keeping our heads above water.
"If there's any other Championship club that's done that in the last couple of seasons we would like to know who they are."
Nottingham Forest manager Billy Davies, a former Derby boss, on his full-time celebrations: "I celebrate the same way on the touchline and I go to the fans, there's no difference. I have no issues at all with coming back here.
"I have no problems with what took place in the past, I am not bitter in any way, I have great memories from here and had some great times at this club. As the Forest manager I expect a bit of stick.
"It was a great finish and a first-class goal. It was a great three points and I was pleased with the discipline and character that we showed."
Live text and stats
Saturday, 22 January 2011
06 Leacock yellow card
21 Moxey two yellow cards, red card
08 Savage yellow card (Bailey 55)
10 Commons (Davies 88)
27 Bueno yellow card
33 Lynch yellow card
07 Anderson yellow card
08 McGugan (Adebola 74)
20 Tudgay (Earnshaw 66 yellow card)
Ref: SalisburyAtt: 33,010
Attempts on target
Attempts off target
90:00+6:47 The referee ends the match.
90:00+5:41 Cross/shot by Ben Davies, Wes Morgan gets a block in.
90:00+4:22 James Bailey gives away a free kick for an unfair challenge on Nathan Tyson. Nathan Tyson restarts play with the free kick.
90:00+2:37 Dean Moxey challenges Robert Earnshaw unfairly and gives away a free kick. Indirect free kick taken by Lee Camp.
90:00+2:37 Sent off Red card for Dean Moxey.
89:12 Booking Joel Lynch is cautioned by the ref for unsporting behaviour.
89:10 Chris Cohen takes a short corner.
88:50 Robert Earnshaw takes a shot. Blocked by Miles Addison.
87:45 Substitution Steve Davies replaces Kris Commons.
86:48 Ben Davies takes a shot. Save by Lee Camp.
85:41 Corner taken by Kris Commons from the right by-line.
84:53 Ben Davies fouled by Wes Morgan, the ref awards a free kick. Centre by Kris Commons, Shaun Barker takes a shot. Save made
by Lee Camp.
83:35 Dele Adebola concedes a free kick for a foul on Shaun Barker. Stephen Bywater takes the indirect free kick.
83:08 Free kick awarded for an unfair challenge on Wes Morgan by Alberto Bueno. Lee Camp takes the indirect free kick.
81:40 Joel Lynch sends in a cross, Dean Leacock makes a clearance.
79:46 Booking Robert Earnshaw is cautioned.
78:34 Paul Anderson provided the assist for the goal.
78:34 GOAL - Robert Earnshaw:Derby 0 - 1 Nott'm Forest Goal scored by Robert Earnshaw from the edge of the penalty area to the bottom left corner of the goal. Derby 0-1 Nottm Forest.
77:46 A cross is delivered by Robert Earnshaw, clearance made by John Brayford.
76:39 Foul by Paul Anderson on Dean Moxey, free kick awarded. Stephen Bywater restarts play with the free kick.
76:17 Guy Moussi takes a shot. Miles Addison gets a block in.
75:34 Inswinging corner taken left-footed by Chris Cohen, Shaun Barker makes a clearance.
75:09 Outswinging corner taken by Chris Cohen.
73:56 Unfair challenge on Ben Davies by Joel Lynch results in a free kick. The free kick is delivered left-footed by Kris Commons
from right wing, Wes Morgan makes a clearance.
73:56 Substitution Dele Adebola is brought on as a substitute for Lewis McGugan.
72:01 Nathan Tyson challenges Miles Addison unfairly and gives away a free kick. Dean Leacock takes the indirect free kick.
70:58 Chris Porter fouled by Wes Morgan, the ref awards a free kick. James Bailey restarts play with the free kick.
69:05 Outswinging corner taken right-footed by Alberto Bueno. Corner from the right by-line taken by Ben Davies, Shaun Barker takes
a shot from close range clearing the crossbar.
68:42 Ben Davies takes a shot. Save made by Lee Camp.
67:48 The ball is crossed by Ben Davies, save by Lee Camp.
67:10 Unfair challenge on Nathan Tyson by Dean Moxey results in a free kick. Chris Cohen takes the free kick.
67:10 Booking Dean Moxey booked for unsporting behaviour.
66:03 Ben Davies takes a outswinging corner from the right by-line played to the near post, Lewis McGugan makes a clearance.
65:20 Nathan Tyson concedes a free kick for a foul on Shaun Barker. Stephen Bywater restarts play with the free kick.
65:20 Substitution Robert Earnshaw joins the action as a substitute, replacing Marcus Tudgay.
61:26 Free kick awarded for an unfair challenge on Miles Addison by Guy Moussi. Free kick crossed right-footed by Ben Davies from
Correction - 60:01 Corner taken right-footed by Ben Davies from the left by-line, Lee Camp makes a save.
60:01 Corner taken from the left by-line by Ben Davies,
60:01 Booking The referee books Alberto Bueno for unsporting behaviour.
57:46 Chris Cohen challenges Alberto Bueno unfairly and gives away a free kick. Direct effort from the free kick comes in from Ben
54:04 Substitution James Bailey joins the action as a substitute, replacing Robbie Savage.
51:41 A cross is delivered by Dean Moxey.
51:11 Lewis McGugan gives away a free kick for an unfair challenge on Ben Davies. Ben Davies delivers the ball from the free kick
right-footed from right wing, clearance by Chris Cohen.
50:36 Nathan Tyson concedes a free kick for a foul on Shaun Barker. Stephen Bywater takes the indirect free kick.
49:15 Ben Davies produces a cross, clearance made by Wes Morgan.
48:16 Robbie Savage challenges Marcus Tudgay unfairly and gives away a free kick. Chris Cohen restarts play with the free kick.
47:57 Alberto Bueno takes a shot. Save made by Lee Camp.
47:33 Lewis McGugan takes a shot. Save by Stephen Bywater.
46:56 Free kick awarded for an unfair challenge on Joel Lynch by Chris Porter. Free kick taken by Chris Cohen.
46:14 A cross is delivered by Chris Porter.
45:22 Joel Lynch gives away a free kick for an unfair challenge on Ben Davies. Indirect free kick taken by Robbie Savage.
45:01 The second half kicks off.
45:00+4:13 The referee calls an end to the first half.
45:00+3:36 Alberto Bueno fouled by Paul Anderson, the ref awards a free kick. John Brayford restarts play with the free kick.
45:00+3:36 Booking The referee shows Paul Anderson a yellow card for unsporting behaviour.
45:00+1:42 The ball is sent over by Chris Cohen, save by Stephen Bywater.
45:00+0:33 Unfair challenge on Marcus Tudgay by Miles Addison results in a free kick. Strike comes in from Chris Cohen from the free
42:35 Nathan Tyson has an effort at goal from deep inside the area missing to the left of the goal.
40:59 Marcus Tudgay takes a shot. Dean Moxey gets a block in.
40:07 The ball is delivered by Miles Addison.
39:10 Ben Davies takes a shot. Blocked by Luke Chambers.
38:31 Unfair challenge on Robbie Savage by Marcus Tudgay results in a free kick. John Brayford takes the direct free kick.
37:13 Paul Anderson crosses the ball. Inswinging corner taken by Lewis McGugan, save by Stephen Bywater.
36:38 Foul by Nathan Tyson on Stephen Bywater, free kick awarded. Stephen Bywater takes the indirect free kick.
34:59 Robbie Savage gives away a free kick for an unfair challenge on Paul Anderson. Lewis McGugan has a direct shot on goal from
the free kick.
34:59 Booking Robbie Savage goes into the book.
32:22 Alberto Bueno takes a shot. Lee Camp makes a save.
31:49 The ball is swung over by Shaun Barker.
31:41 The ball is delivered by Kris Commons.
31:14 Outswinging corner taken by Ben Davies from the right by-line, Luke Chambers manages to make a clearance.
31:03 Kris Commons produces a cross, Wes Morgan makes a clearance.
30:27 Outswinging corner taken from the right by-line by Ben Davies.
30:21 The ball is swung over by Alberto Bueno, clearance made by Wes Morgan.
28:44 Guy Moussi fouled by Alberto Bueno, the ref awards a free kick. Lewis McGugan shoots direct from the free kick.
28:13 Free kick awarded for a foul by Ben Davies on Guy Moussi. Luke Chambers takes the free kick.
24:53 Chris Porter takes a shot. Clearance by Luke Chambers.
22:38 Dean Leacock challenges Nathan Tyson unfairly and gives away a free kick. Lewis McGugan takes the free kick.
22:38 Booking Dean Leacock is shown a yellow card for unsporting behaviour.
19:35 The ball is swung over by Dean Moxey, Wes Morgan manages to make a clearance.
18:39 Free kick awarded for an unfair challenge on Ben Davies by Joel Lynch. Free kick crossed by Ben Davies, clearance made by
17:55 The referee blows for offside against Nathan Tyson. Free kick taken by Shaun Barker.
15:38 Shaun Barker gives away a free kick for an unfair challenge on Guy Moussi. Shot comes in from Lewis McGugan from the free
kick, save made by Stephen Bywater.
11:47 Unfair challenge on Wes Morgan by Kris Commons results in a free kick. Lee Camp takes the indirect free kick.
11:27 Kris Commons takes a shot. Blocked by Wes Morgan.
9:03 The ball is delivered by Dean Moxey.
8:04 The offside flag is raised against Nathan Tyson. Stephen Bywater takes the indirect free kick.
6:33 The assistant referee signals for offside against Nathan Tyson. Shaun Barker takes the indirect free kick.
6:01 The ball is swung over by Dean Moxey, clearance by Joel Lynch.
4:51 Centre by Paul Anderson. Inswinging corner taken by Robbie Savage from the left by-line.
4:00 Marcus Tudgay concedes a free kick for a foul on Ben Davies. Direct free kick taken by Robbie Savage.
3:25 Lewis McGugan gives away a free kick for an unfair challenge on Kris Commons. Dean Leacock takes the indirect free kick.
2:46 Guy Moussi takes a shot. Shaun Barker gets a block in.
0:25 The ball is crossed by Alberto Bueno.
0:00 The referee starts the match.
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