Birmingham 0-0 Southampton
Southampton lost further ground on Championship leaders West Ham as they played out a draw against promotion hopefuls Birmingham at St Andrew's.
The hosts had the better chances in snowy conditions with Guirane N'Daw heading just wide from close range.
Marlon King saw his low 18-yard side-foot superbly tipped round the post by Saints keeper Kelvin Davis who later saved well at the feet of Adam Rooney.
Southampton also had Danny Fox sent off for two bookable offences late on.
The result keeps Saints second but they fall four points behind the Hammers while Birmingham are in fifth place and nine points behind the leaders with a game in hand.
Snow and wind made life difficult for both sides but Birmingham started the stronger, with midfielder N'Daw, back in the side after his Africa Cup of Nations campaign with Senegal was brought to a premature end, heading narrowly wide after eight minutes.
It was the closest either side came to scoring with neither keeper tested in an uneventful first half.
That changed within 38 seconds of the restart as David Murphy burst down the left and found King, whose strike was palmed around a post by Davis.
New Saints signing was introduced for his debut just minutes into the second half, but it was Davis who soon in action again as he saved from N'Daw.
Boaz Myhill in the Birmingham goal had still to make a stop as Saints failed to capitalise on a defensive mix-up by the hosts with 25 minutes remaining.
Fox was shown a second yellow for a foul on Chris Burke with seven minutes remaining but Chris Hughton's side were unable to make their numerical advantage count.