Goals from Jason Scotland and Tommy Smith gave Town the points in front of the biggest crowd of the season at Portman Road.
Scotland struck on 18 minutes, rounding Shane Higgs to put the ball into the empty net after Jake Livermore had found him with an incisive pass.
Robert Snodgrass levelled the scores for the visitors on 74 minutes but Smith, who wasn't initially in the starting X1, headed the winner for Town eight minutes from time with Leeds finishing the game with 10 men after former Blue, Alex Bruce, was sent-off.
Town were forced to make a change before kick-off with Damien O'Dea, who was named in the starting line-up, aggravated the knee injury that has dogged him recently in the warm up, Smith coming in.
Livermore came in for his full debut for Blues in one of three changes Roy Keane made to the side that was beaten at Reading in midweek, Mark Kennedy and Tom Eastman also included in the line-up.
The Town fans gave a standing ovation to Richard Naylor on his return to Portman Road, Bruce also getting a warm reception from the home fans as the two former Blues lined up in the Leeds' defence.
Naylor blocked the progress of Jaime Peters as the Canada international attempted to burst into the box, Smith then denying Davide Somma at the other end before Blues got the breakthrough on 18 minutes. Livermore the creator with a pass to set Scotland in on goal and the striker rounded Higgs before planting the ball in the empty net.
Scotland dragged a left foot shot wide after Bruce had given away possession, Peters crowded out inside the Leeds' box as Town threatened a second.
In a first-half of few clear cut chances, Leeds were restricted to long shots from Somma and Jonathan Howson that went high and wide, while a Naylor header was cleared inside the Town box as the Elland Road skipper looked to mark his return to the club he called home for 15 years with the equaliser.
The last action of the half saw Somma cut inside from the Leeds' left but his shot failed to trouble Marton Fulop while at the other end, Higgs had a scare when Neill Collins chested Andros Townsend's cross at him from close range.
Town made an early change in the second-half with Eastman making way for Tamas Priskin, Peters dropping in at right-back.
Bruce picked up the first yellow card of the game for a foul on Townsend and Blues should have extended the lead from the free-kick, the ball falling to Scotland six yards out but he lashed it over the bar.
Bradley Johnson sent a free-kick well over from 25 yards, while at the other end Gareth McAuley was a foot wide with a header from Peters' cross.
Leeds were forced into a change with Higgs appearing to twist his knee as he covered his goal from McAuley's header, Jason Brown the replacement.
Naylor then followed Bruce into referee Keith Hill's notebook for a foul on Livermore.
Townsend had a shot deflected over by Bruce, the Tottenham loanee then setting up Scotland who jabbed the ball goalwards, Brown equal to the task.
Priskin smashed a shot over after a break down the Town left before Leeds made a double change for the last 16 minutes, Watt and Luciano Becchio on for Johnson and Neil Kilkenny.
The change had immediate dividends, Watt squaring for Snodgrass to find the net at the far post.
Bruce's return ended 12 minutes early, the defender caught Townsend as he stretched for the ball and referee Hill reached for a second yellow card and then red.
Town made a second change, Connor Wickham on for Scotland and Blues got an immediate response, Smith getting on the end of Carlos Edwards' delivery to beat Brown with a header for his second goal of the season.
Blues made a third change before the restart, Troy Brown on for Edwards. Townsend smashed a shot wide, Grant Leadbitter and Collins picked up yellow cards before McAuley jabbed the ball clear in a scramble as Leeds pressed for an equaliser.
The win takes Town back into the top six ahead of the international break and extends the unbeaten run against Leeds to seven games.&nbsp;
Town: Fulop, Eastman (Priskin 52), McAuley, Smith, Kennedy, Edwards (Brown 83), Leadbitter, Livermore, Peters, Townsend, Scotland (Wickham 81). Subs not used: Murphy, Healy, Murray, Delaney. Booked: Leadbitter.
Leeds: Higgs (Brown 63), Bruce, Collins, Naylor, McCartney, Howson, Faye, Kilkenny (Watt 73), Johnson (Becchio 73), Somma, Snodgrass. Subs not used: Gradel, Clayton, Hughes, Nunez. Sent-off: Bruce. Booked: Bruce, Naylor, Collins.