Their lead at the top was cut to six points as lowly Wycombe earned a richly deserved point at Elland Road against an off-colour Whites.
Simon Grayson felt his side lacked energy after their FA Cup heroics at Manchester United the previous week and he will have to juggle his resources skilfully to cope with a heavy fixture schedule in the coming weeks, weather permitting.
Stadium staff worked long and hard to get the game on and more than 24,000 fans battled through snow and ice to get there.
Apart from Norwich, all United's rivals were inactive so it seemed a formality that Leeds would roll over second-bottom Wycombe and plump up their promotion cushion.
That scenario looked likely as Jonny Howson's 22-yard shot defeated goalkeeper Scott Shearer after only four minutes.
Wycombe could have been forgiven for folding. Instead, they went on to give one of the most accomplished displays by a visiting team at Elland Road this season.
Both Jon-Paul Pittman and Scott Davies hit the woodwork, Neil Kilkenny cleared off the line and the Chairboys had several half chances in and around the box as Leeds struggled to match their opponents' movement and slick passing.
Although Bradley Johnson had a header hacked off the goal-line, Leeds were lucky to be up at the interval and their overall performance failed to improve in the second half.
Wanderers got their reward on 63 minutes when another United move broke down and the ball was quickly transferred to the game's outstanding player, Pittman, who cut past Naylor and fired a fine angled drive past Casper Ankergren.
Grayson sent on Max Gradel, who has sparkled as a substitute during his loan spell from Leicester, but this time he was unable to give jaded Leeds the required impetus as Wycombe looked as capable as the home side of winning the game.
United certainly looked as through they had left some energy behind at Old Trafford and, although they are still in a very strong position, can't take promotion for granted.
Want-away star striker Jermaine Beckford, lacking ammunition in this game, will be hard to replace in terms of goals so it promises to be an intriguing few weeks both on the field and off it.
Meanwhile, in the only other League One game at the weekend, in-form Norwich cemented second spot with a 3-1 home win against Exeter, United's next scheduled opponents.
Leeds United: Ankergren, Crowe, Naylor, Kisnorbo, Johnson (White 66), Howson, Doyle, Kilkenny, Snodgrass (Gradel 66), Becchio (Grella 83), Beckford.
Subs (not used): D Martin, Prutton, Michalik, Bromby.
Wycombe: Shearer, Hunt, Hinselwood, Westwood, Woodman, Davies, Mousinho, Docherty, Beavon, Pittman, Harrold.
Subs (not used): Oliver, Bloomfield, Young, Green, Phillips.
Referee: David Webb (County Durham).
Attendance: 24,383.