An injury-time own goal from Leyton Orient defender Charlie Daniels salvaged a point for Leeds in a 1-1 draw at Brisbane Road.
Simon Grayson's side dominated throughout but were unable to make the most of their superiority and even fell behind to Tamika Mkandawire's 83rd-minute strike.
However, the Whites claimed a deserved leveller in stoppage-time as Daniels inadvertently put through his own net.
Leeds earned nine corners in the first half but were denied a breakthrough as Orient keeper Jamie Jones made fine saves to deny Gary McSheffrey and Leigh Bromby.
Orient, by contrast, were restricted to token efforts by midfielder Sean Thornton and Jason Demetriou which posed no problems for United keeper Casper Ankergren.
Leeds maintained the relentless pressure after the break, while Orient replaced leading scorer Scott McGleish with the greater physical presence of French substitute Jonathan Tehoue.
Orient came into the game more during the closing 25 minutes and grabbed a shock lead when Mkandawire headed home Nicky Adams' cross for his sixth goal of the season.
But just when it seemed the Londoners had gained a remarkable backs-to-the-wall win, Daniels turned the ball into his own net in a goalmouth scramble.
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