Simon Grayson remained defiant despite this first defeat of the season to bogey side Millwall at The Den.

It proved to be unlucky 13 for the League One leaders, as their third successive loss in South London was confirmed when goals from Neil Harris and Gary Alexander sandwiched Patrick Kisnorbo's 11th-minute leveller.

Grayson, however, said: "We are delighted to be at this stage of the season and this is our first defeat. When you are the only team in the country unbeaten, you will take that for certain, but it is how you react to defeat, and we have a group of players that do respond to adversity.

"I'm disappointed because I wanted to have gone through the course of the season unbeaten, but the likelihood of that was very minimal."

Millwall took the lead when Harris headed home Hackett's free-kick but Grayson claimed a push on Andy Hughes went unnoticed. United levelled from a set piece, Kisnorbo thumping home a rebound from his initial header.

Substitute Alexander settled it seven minutes from time as he rose above Hughes to head in a cross, but United almost drew as Tresor Kandol hit the bar and Paul Robinson cleared off the line.

Millwall: Forde; Dunne, Robinson, Craig, Smith; Hackett, Abdou, Laird, Schofield; Morrison (Alexander 61), Harris (Price 89). Unused substitutes: Sullivan, Bolder, Grabban, Martin, Henry.

Leeds United: Ankergren; Bromby, Naylor, Kisnorbo, Hughes; Snodgrass (Gradel 78), Howson, Doyle (Kilkenny 88), Johnson; Beckford, Vokes (Kandol 70). Unused substitutes: Fielding, Crowe, Prutton, Michalik.

Referee: M Clattenburg.