|Feeney 31, Keogh 76||Venue: The Den
MILLWALL moved to within four points of the play-off positions after Andy Keogh's winner settled an end-to-end encounter with Derby at The Den.
Liam Feeney's first goal of the season had given the Lions the lead on the half-hour mark, but the game was in the balance after Will Hughes' leveller early in the second period.
But Keogh diverted substitute Scott Malone's cross into the far corner to snatch all three points and extend the club's unbeaten run to nine matches.
Feeney and Keogh both came into the side to replace injured duo James Henry and Darius Henderson, while assistant manager Joe Gallen took control of first-team affairs with Kenny Jackett suffering from flu.
The first-half was largely a scrappy affair in which both teams struggled to get the ball down and create chances going forward.
Liam Trotter was the first to chalk up an opportunity for the Lions after only three minutes when he found himself in space just outside the area.
The midfielder checked onto his left foot and fizzed a shot goalwards that stung the palms of Adam Legzdins,.
Millwall went close to opening the scoring in the 15th minute when Keogh's clever flick-on gave Chris Wood the opporunity to shoot from 25-yards out, but Legzdins reacted quickly to fist the ball away.
Feeney then skipped past the challenge of Gareth Roberts before playing a deft through-ball into Wood, but his over-hit cross evaded the onrushing Keogh.
But the opening goal arrived on the half-hour mark when Shane Lowry's teasing cross was finished off by Feeney, who slammed the ball first-time into the top corner after a darting run into the box.
The linesman initially raised his flag for offside but after consulting referee Darren Drysdale, the decision was reversed and the goal was allowed to stand.
With half-time approaching, Keogh played a neat one-two with Trotter before delivering a cross towards the head of Wood, but the ball was inches too high for the West Brom loanee.
The Rams made an enterprising start to the second period and on 49 minutes, forward Conor Sammon found himself in acres of space on the edge of the area and fired a shot just over the bar.
But Millwall's slack marking was punished second time around when Hendrick's pass found Hughes 20-yards out and the 17-year-old duly fired the ball into the top corner to equalise.
The Lions responded through Spurs loanee Adam Smith, who burst forward with a slaloming run, beating four or five men, before playing a one-two with Wood and striking a well-hit shot just over Legzdins' goal.
In the 70th minute, Malone carried the ball from inside his own half and into the final third but Keogh could not capitalise on the winger's through-ball.
However, the pair combined to restore Millwall's lead moments later when Malone managed to nick possession in the Derby area before squaring to Keogh, who curled the ball inside the far post.
Derby had a strong shout for a penalty waived away late on after former Lion Theo Robinson went down under Danny Shittu's challenge, before Wood's header was disallowed for a push at the other end.
Forde was called into action twice in quick succession to deny Rams sub Michael Jacobs while, in stoppage time, Jimmy Abdou blocked Robinson's goal bound effort to secure a nerve-biting victory.
Millwall: Forde, A.Smith, Lowry, Abdou, Shittu, Beevers, Feeney, Trotter, Keogh, Wood, C.Taylor (Malone, 45+2mins). Subs not used: M.Taylor, J.Smith, Osborne, N'Guessan, Batt, Wright.
Derby County: Legzdins, Brayford, Roberts, Coutts, Robinson, Sammon (Jacobs, 80mins), O'Connor, Keogh, Bryson, Hughes, Hendrick. Subs not used: Deeney, Buxton, Tyson, Freeman, Davies, O'Brien.