Derby County progressed to Round 4 of this season's FA Cup with a Third Round replay 5-3 penalty shoot-out victory over Millwall after a 1-1 draw after 120 minutes.

After a scoreless 90 minutes in which Derby came closest when Chris Porter hit the bar the two sides were still unable to be separated after a further 30 minutes of extra time.

Steve Morison's goal early in the second period of extra time looked to have put Millwall into the next round, but his effort was cancelled out by substitute Steve Davies late on.

In the shoot-out Derby slotted away all five of their penalties, with Stephen Bywater making the crucial save from Danny Schofield to put Derby through and set up a home tie with either Brentford or Doncaster Rovers.

Derby's starting line-up displayed two changes from the 4-1 defeat to Scunthorpe United on Saturday.

Nicky Hunt was unavailable under the terms of his loan from Bolton Wanderers so Lee Croft took his place, with Paul Green reverting to right-back.

Kris Commons, whose goal forced a replay in the original tie, was handed a starting berth in place of Rob Hulse.

The first opening of the game was carved out by Derby  after ten minutes as Pearson set off on a lung-bursting run forwards from midfield beating three Millwall players but with Forde to beat he fired straight at the goalkeeper who turned the ball away.

Derby almost broke the deadlock on twenty-two minutes when Croft's well-flighted delivery from the right was met with a firm header by Porter, but the ball whistled just wide.

Bywater kept Millwall out ten minutes before the break with a smart save diving to his right to turn away Grabban's deflected shot from 25 yards, Millwall's first effort of the night on target.

Derby were forced into a change five minutes before the break when Miles Addison was hit with a reoccurrence of the foot injury which has blighted his season.

That meant a return to action a little earlier than anticipated for Shaun Barker who was named on the bench after recovering from the thigh injury which had kept him out of action since the end of November.

Millwall tried their luck with two long-range efforts in the closing minutes of the half, but on both occasions Bywater was equal to the shots on goal.

Commons came within a matter of inches of breaking the deadlock in first half injury time but his powerful shot on the turn from 25 yards was just off target.

The Scotland international had the first effort of the second period when latching onto a Croft ball over the top but stretching to reach the ball he couldn't direct his effort on target as Derby started the second period strongly.

Steve Davies came on for Croft on the hour and he had an immediate impact with a shot on the turn after Forde failed to keep hold of a Derby corner, but the Millwall defence managed to hack the ball away.

On 67 minutes Derby thought they had finally got the goal their play deserved, but Porter's powerful effort from eight yards out from Pearson's cross cannoned back off the crossbar and Millwall survived.

Commons was replaced by Gary Teale with eleven minutes remaining as Derby made their final change of the night after picking up a slight knock. Teale immediately delivered a telling cross from the right which was met by a diving Davies with his head, but Forde saved well at his near post.

Millwall wasted a good opportunity with five minutes remaining on the break when Martin lashed a shot goalwards from 20 yards when he had Morison unmarked in the box. Morison had a golden chance to win it for Millwall with seconds left but after rising highest to meet Schofield's cross he could only head straight at Bywater.

Despite a number of late bursts forwards Derby couldn't find that elusive goal and both sides had to settle for a further 30 minutes of extra time.

Davies came agonisingly close with a free-kick from 20 yards midway through the first period of extra time, while for Millwall Morison again tested Bywater with another powerful header which the goalkeeper gathered.

Bywater was beaten though by Barron a few seconds later with a thunderous 20 yard effort, but the ball crashed back off the inside of the post and back into play.

That was the final act of the first period of extra time, but within a few minutes of the second period Millwall made the breakthrough.

Derby failed to clear a corner from Hackett and the loose ball was rammed home from close range by Morison to spark off wild celebrations in the Millwall end.

Davies lashed a shot in at goal straight from the kick-off in a neat Derby move but Forde turned the ball away to deny the Rams an immediate comeback.

But Davies didn't have to wait too long to get his goal, and the substitute used his pace to burst through the Millwall defence and calmly lift the ball over the advancing Forde to bring Derby onto level terms with only six minutes to go for his first goal of the season.

It sparked a late rally from both sides going for the winner, but in the end the two sides had to settle for a penalty shoot-out to decide who would make it through to Round 4.

Steve Davies, Robbie Savage, Chris Porter, Gary Teale and Dean Moxey all converted from the spot to put Derby through. Martin, Smith and Morison all slotted away from the visitors, but Bywater's excellent stop from Schofield was enough to put Derby through.

Derby 1-0 Millwall (Davies)
Derby 1-1 Millwall (Martin)
Derby 2-1 Millwall (Savage)
Derby 2-1 Millwall (Schofield effort saved)
Derby 3-1 Millwall (Porter)
Derby 3-2 Millwall (Smith)
Derby 4-2 MIllwall (Teale)
Derby 4-3 Millwall (Morison)
Derby 5-3 Millwall (Moxey)

Derby will face either Brentford or Doncaster Rovers at home in Round 4.