Marlon King bagged a brace as Birmingham outlined their promotion credentials by hammering nine-man Millwall.

Blues were on the back foot for the majority of the first half but they took their chance after the sorry hosts completely lost their discipline.

Curtis Davies gave Chris Hughton's side an 18th-minute lead against the run of play before the Lions' chances were hampered when Shane Lowry was sent off for an off-the-ball incident with Nikola Zigic.

Zigic was at the centre of the action again as he was felled by Alan Dunne's tackle from behind, with the defender also given a straight red card.

From there on, Birmingham ran riot as strikes from King and then Chris Burke ensured the points would go to the midlands outfit.

Further efforts from Adam Rooney, another from King and Nathan Redmond ensured Birmingham extended their unbeaten run to six matches in some style.

Millwall manager Kenny Jackett made five changes to the side that drew at Dagenham & Redbridge in the FA Cup and it was one of those replacements who nearly put the hosts in front.

Hamer Bouazza picked out Dany N'Guessan at the near post but the striker could only head wide.

On-loan Tottenham striker Harry Kane then had his effort from Bouazza's corner cleared off the line by a perfectly positioned Jean Beausejour as the Lions continued to belie their lowly league position.