Rory Delap's first goal for two years gave Paul Sturrock his second win as Southampton boss.
Delap's spectacular bicycle kick decided a game in which keepers Antti Niemi and Kasey Keller played big roles in keeping it tight.
Southampton's Niemi produced great saves to deny Jermain Defoe and Jamie Redknapp, while Robbie Keane wasted a good second-half chance.
An acrobatic save from James Beattie was the pick of Kasey Keller's efforts.
A foul on David Prutton 25 yards out gave Beattie the chance to clip a fourth-minute free-kick around the Spurs wall but just wide of the target.
Freddie Kanoute, operating on the right of midfield, gave Spurs plenty of attacking options.
23 mins: Keller denies Beattie
28 mins: Niemi saves from Defoe
50 mins: Fernandes misses from eight yards
64 mins: Delap puts Saints 1-0 up.
A stinging drive from Defoe was gathered by Niemi at the second attempt and Kanoute then tested the Finn with a firm shot.
At the other end, the ball broke kindly for Danny Higginbotham whose cross-shot cannoned behind for a corner off Ledley King.
But Spurs had to rely on Keller to keep them level on 23 minutes when Beattie reacted sharply to divert the ball goalwards where the big American keeper reacted brilliantly to save.
Defoe's pace was a threat and he escaped from Paul Telfer to fire in a shot which Niemi saved superbly down low to his left.
Kevin Phillips was Saints' biggest threat and he latched on to Fabrice Fernandes's cute pass but his lob over the advancing Keller rolled inches wide of the post.
James Beattie and Anthony Gardner battle it out
Telfer's powerful run produced an inviting cross for Beattie whose acrobatic volley flew well over.
Before half-time, Michael Brown's shot stung Niemi's hands and Defoe dragged his shot wide when well-placed.
Spurs sent on Redknapp for Johnnie Jackson at the start of the second half and three minutes later they were forced into a second change with Stephen Kelly replacing the injured Christian Ziege.
Southampton started the second half brighter and Beattie muscled his was past Anthony Gardner to pull the ball back for Fernandes who blasted wide of the target.
Spurs were under the cosh and from the last of three corners in quick succession, Southampton took a 66th minute lead in spectacular fashion.
Claus Lundekvam headed the ball back across goal and Delap launched himself into a stunning bicycle kick to leave Keller standing.
Spurs looked for a quick response and Niemi was again forced into action from Redknapp's powerful 25-yard shot before Defoe headed over from eight yards.
Delap had a chance to wrap the game up when Beattie rounded Keller and pulled the ball across the face of goal, but Saints' record signing blazed wide of an open goal.
Southampton: Niemi, Dodd, Lundekvam, Higginbotham, Telfer,
Fernandes (Ormerod 76), Delap, Prutton, Folly,
Phillips (Anders Svensson 76), Beattie. Subs not used: Smith, Hall, Pahars.
Tottenham: Keller, Carr, Doherty, Gardner,
Jackson (Redknapp 45), Brown (Dalmat 77), King, Keane,
Ziege (Kelly 48), Kanoute, Defoe. Subs not used: Hirschfeld, Postiga.
Booked: Doherty, Ziege.
Referee: C Foy (Merseyside).