SOUTHAMPTON have edged ahead of Sunderland in the battle for Premiership survival.
Egil Ostenstad's 13th goal of the season midway through the first half left Sunderland with an uphill task at Roker Park.
Peter Reid's men pressed hard for an equaliser and substitute Niall Quinn hit the post twice be fore the break.
But Southampton held firm, aided by tame finishing that has been Sunderland's trademark this season and threatens to cost them their place in the top flight.
Southampton's win lifted them above Sunderland and Coventry to 15th, three points above the relegation zone.
Sunderland, 1-0 winners at Middlesbrough on Saturday, have yet to string together back-to-back Premiership wins this season and are two points above the bottom three with only two matches to save themselves.
Matt Le Tissier, booked in for a hernia operation at the end of the season, missed his third successive match because of a hamstring strain.
Sunderland winger Michael Gray, playing at left back for the second successive match, started but could not finish a promising seventh minute move. Gray broke from inside his own half then raced towards Southampton's box where he met Chris Waddle's cross with a volley that flew over the crossbar.
Ostenstad headed over at the far post from Neilson's cross but the Norwegian was not to be denied, and when Howe failed to cut out Neilson's cross in the 22nd minute he brought the ball down neatly and placed a low shot under Lionel Perez.
Reid immediately made a tactical substitution, sending on Quinn for Allan Johnston and switching from 4-5-1 to 4-4-2, with Quinn forming a twin spearhead with Paul Stewart.
Southampton got a firm grip on the match in the last IS minutes and Sunderland were looking ragged long before the final whistle.