Millwall are level with Bradford City at half time of their FA Cup third-round clash, after Scott McDonald cancelled out Billy Knott's strike.
The visitors took the lead when Knott poked home after just six minutes from a corner, as the visitors capitalised on their fast start.
Millwall were visibly frustrated, and that only increased when the officials ruled out a Ricardo Fuller strike for offside from a Danny Shittu knock down.
The League One side almost doubled their advantage shortly afterwards, but Andy Halliday blasted James Hansen's pass over the bar when well placed, before Fuller went close again for the home side as his shot fell narrowly wide.
Millwall's pressure paid off shortly after when Scott McDonald steered a header into the corner, after neat work on the wing by Lee Martin.
The Championship side increased the pressure as they searched for a half-time lead, but it was Bradford who almost snatched a goal as Knott had a shot well saved by Forde.
