Southend boosted their League One play-off chances by inflicting a 1-0 defeat on Leeds, who have appointed Gary McAllister as manager.
Lee Barnard's first goal on his full Shrimpers debut condemned Leeds to their third match without a win.
The former Spurs forward touched the ball home on 41 after goalkeeper Dave Lucas could only get a hand to Steve Hammell's 25-yard free-kick.
Leeds had created some good opportunities in an even first half. David Prutton and Andy Hughes fired shots straight at Darryl Flahavan, while Tresor Kandol headed wide and Jermaine Beckford headed into the side-netting from close range.
Southend had recovered from the early pressure and forced Lucas to make saves from Mark Gower and Charlie MacDonald.
The Shrimpers started the second half brightly with Adam Barrett heading over and Barnard shooting just wide.