Derby County go in at half time on level terms with Millwall, but may consider themselves lucky not to be trailing Ian Holloway's men at the interval.
The Rams, who started the game one point behind leaders Norwich City, began on the front foot with Jamie Ward twice going close to breaking the deadlock inside the opening minutes.
Millwall, looking to bounce back from a midweek defeat at home to Birmingham City, found chances to be at a premium in the early stages as Lee Gregory's shot was blocked by the Derby defence.
As the half progressed, the Lions started to cause problems in attack when Gregory and Matthew Briggs came close to scoring midway through the half.
However, they nearly found themselves trailing and can be thankful for David Forde's stop from a Ward strike that seemed destined for the top corner.
Gregory was at the centre of much of Millwall's creativity and he squandered another chance after latching on to Scott McDonald's cross, but couldn't find a way past Lee Grant.
At the end of an ill-tempered 45 minutes, which saw six yellow cards, Aiden O'Brien tried to forge an opening only to be kept out by a resolute Rams defence.
