Southampton have lost their 2011 unbeaten home league record in their last match with a 1-0 defeat to Bristol City.
In an even first half, Albert Adomah was unlucky when he ended his strong run with a wayward finish.
Morgan Schneiderlin came close soon after, but his spectacular effort was saved by David James.
Adomah, who was a constant threat for the visitors, caused problems again on 33 minutes but his shot was tipped around the post by Kelvin Davis.
After two wasted chances by Saints striker Guly Do Prado, the away side made the breakthrough with 12 minutes to play when Stephen Pearson slotted in following Davis's save.
The Saints could have been level in the final five minutes, but Do Prado's effort again flew disappointingly wide.