Derby County came from a goal down to ensure their interest continues in this season's FA Cup with a 1-1 draw at League One Millwall this afternoon.

Lewis Grabban gave Millwall the lead early in the second half with a towering header, but Derby hit back immediately as Kris Commons lashed his second goal of the season.

That means both sides will have to do it all over again in a replay at Pride Park Stadium a week on Tuesday.

The Rams signalled their intent to attack from the off by selecting three strikers in the form of Commons, Rob Hulse and Chris Porter to take on the Lions.

In total, there were three changes from the side that started in the goalless draw at Newcastle United on Monday evening with Porter coming in for the ineligible DJ Campbell, while the suspended Robbie Savage and Jay McEveley were replaced by Commons, Porter and Dean Moxey.

New loan signing Lee Johnson was named amongst the substitutes after joining on a month's loan from Bristol City on Friday afternoon, as was young scholar Callum Ball who was also drafted into the squad yesterday.

In the absence of skipper Savage, the captain's armband was handed to goalkeeper Stephen Bywater to lead the Rams into battle.

Nigel Clough predicted Derby wouldn't get much time on the ball in this Cup tie against their League One opponents, and in the opening stages his point was proven as Millwall quickly got in the faces of the Rams players.

The Lions had the first chance of the game with ten minutes gone, but Marc Laird could only hit the side netting after cutting inside from the right. He should have done better considering the time and space he had.

Straight down the other end Porter played strike partner Hulse clear on goal for Derby's first chance, but the big number nine dragged his left-foot shot off target although the angle was always against him.

Derby were producing some neat one-touch football in midfield and were finding themselves in some good attacking areas to exert pressure on the Lions defence, with Connolly finding space to deliver a number of dangerous crosses from the right.

A Pearson free-kick was met with a firm header by Porter on eighteen minutes but Forde saved easily as Derby enjoyed a spell of pressure.

Millwall showed they have pace in abundance up front with Morison and Grabban always looking dangerous and Morison's hard work created an opening for Martin twenty yards out but Buxton blocked his low effort.

Commons tried his luck from range towards the halfway point of the half with a low effort from twenty-five yards which Forde saved comfortably.

Millwall cranked up the pressure as the game approached the half-hour with Martin beating Connolly down the left and delivering a low cross that Green hacked away inside the six-yard box and Smith also flashed a shot wide from long range which Bywater had covered.

The game was being played at a really high tempo, which suited both sides who had their minds focused on attacking and getting the job done without the need of a replay.

Grabban's pace was almost the difference ten minutes before the break when Grabban was played clear on goal by Morison in a two-on-one situation, but with just Bywater to beat he fluffed his lines and sliced his shot wide. It was a big let-off for Derby.

And Derby almost made the home side pay in first-half injury time after a good passing move with the ball eventually worked to Commons whose low cross caused panicin the Millwall defence but they were able to survive.

At the break Derby were forced into a change with new signing Johnson coming on for Hendrie who picked up a hamstring problem in the first period.

With just a few minutes played in the second half, Millwall took the lead.

Grabban pulled away from his marker intelligently inside the box and met Laird's deep cross with a looping header which beat Bywater all ends up and drifted into the top corner to spark off pandemonium at the Den.

Rather than hide in their shells in such an intimidating atmosphere, Derby rolled up their sleeves and immediately hauled themselves back onto level terms. Millwall were unable to clear the ball from inside their box and Commons took advantage with a powerful drive across Forde into the far corner.

It was just the sort of reaction Nigel Clough was calling for from the technical area. And he got it within just three minutes.

Commons, spurred on by his goal, tried his luck again two minutes later but he wasn't able to test Forde.

A deflected shot from Martin almost restored Millwall's lead on the hour, but the ball whistled just wide.

The game was being played at a hundred miles an hour and there was no holding up by either side, but chances were at a premium.

When a chance did come with twenty to go, Derby almost took it. Addison played Porter in down the right and his low cross was guided towards goal by Hulse, but he couldn't work his effort on target.

Seconds later Derby had another chance, but again Forde wasn't tested as Commons blasted powerfully wide from twenty yards.

Steve Davies replaced Rob Hulse for the final fifteen minutes in attack, but it was Millwall enjoyed the better of the game and Green was called upon to clear Frampton's header off the line from a corner. Seconds later Frampton tried his luck again with a goalbound shot which Addison threw his body in the way off.

Davies almost announced his return from injury with a goal with ten to go but his free-kick from thirty yards clipped the top of the net and drifted over the bar.

As the final minutes approached Millwall went close through Morsion but his snap-shot from eighteen yards was off target.

Three minutes of time were added by the officials, but neither side could make the breakthrough and will have to battle it out again at Pride Park a week on Tuesday.

Millwall: Forde, Frampton, Robinson, Grabban (Price 87), Martin (Schofield 87), Hackett, Craig, Morison, Smith, Laird, Abdou
Subs: Sullivan, Dunne, Ward, Grimes, Fuseini
Booked: Laird, Morison
Goals: Grabban (49)

Derby County: Bywater, Connolly, Buxton, Addison, Moxey, Pearson, Hendrie (Johnson 46), Green, Commons (Teale 90), Hulse (Davies 76), Porter
Subs: Deeney, Mendy, Pringle, Ball
Booked: Hulse
Goals: Commons (52)

Referee: Mr J Linington