FA CUP heroes Bradford City moved up to within a point of the play-off places with a comfortable win.
Bantams striker James Hanson scored both goals either side of the half-hour mark as his side took another positive step towards the play-offs.
Talisman Hanson opened the scoring in the 21st minute, but that was only after the relegation-threatened hosts had been denied by the woodwork.
Elliot Omozusi superbly found on-rushing midfielder Romain Vincelot, and he crashed a shot against the crossbar.
As the ball rebounded out into the City box, David Mooney then dragged his shot wide.
Hanson was brilliant when opening the scoring. He latched on to Mark Yeates’s through-ball, chested the ball down and volleyed an unstoppable effort past stunned Orient goalkeeper Alex Cisak.
It got even better 11 minutes later.
This time Filipe Morais flung over a super free-kick for Hanson, and he glanced a neatly-placed header into the bottom corner. It was all Bantams at that point, with Morais the next to go close, inches wide from 25 yards.
Boss Phil Parkinson gave Hanson and Andrew Davies a rest when he replaced them with Francois Zoko and Gary MacKenzie at half-time and it should have been 3-0 when Billy Clarke fired straight at Cisak.
The hosts went close through ex-Bantam loanee Chris Dagnall in the closing minutes, but they had been second best all night.
Leyton Orient: Cisak, Omozusi, Clarke, Lowry, Sawyer, Pritchard (McAnuff, 72), Vincelot, Bartley (Wright, 64), Cox (Hedges, 59), Mooney, Dagnall. Unused substitutes: Grainger, Baudry, Lisbie, Batt.
Bradford City: Pickford, Darby, McArdle, Davies (MacKenzie, 46), Meredith, Morais, Liddle, Halliday, Yeates, Hanson (Zoko, 46), Clarke (Sheehan, 87). Unused substitutes: Williams, Knott, Kennedy, Routis.
Referee: Trevor Kettle.