Alan McCormack sealed the points for the Londoners early in the second half as Warburton's side remain one point adrift of Wanderers with a game in hand.
In contrast, Orient lost ground in the race for automatic promotion as Russell Slade's men slipped four points behind Brentford - who have played two fewer games - after being held to a 1-1 draw with the Saddlers.
Jordan Spence reduced the arrears on 81 minutes before Ben Reeves equalised shortly after. There was yet more drama, though, as Dean Lewington pounced in the closing stages to snatch all three points.
Consequently, the Dons close move three points adrift of Peterborough United, who occupy the final playoff place.
At the other end of the table, Notts County ended their six-game winless streak to breathe fresh life into their survival bid with a 4-1 victory over Carlisle United at Meadow Lane.
Haydn Hollis and Ronan Murray fired the Magpies into a 2-0 half-time lead, before the former trebled his team's advantage shortly after the break.
James Berrett reduced the arrears on 57 minutes, but it proved a mere consolation as Gary Liddle re-established the three-goal lead once again.
Shaun Derry's men remain bottom of the standings, but sit just three points adrift of safety.
Results in full: Brentford 3-1 Coventry City, Colchester United 2-2 Bristol City, Gillingham 1-3 Crewe Alexandra, Notts County 4-1 Carlisle United, Oldham Athletic 1-0 Crawley Town, Peterborough United 0-1 Rotherham United, Port Vale 3-2 Tranmere Rovers, Shrewsbury Town 2-1 Bradford City, Stevenage 2-3 MK Dons, Sheffield United 0-2 Wolverhampton Wanderers, Swindon Town 1-0 Preston North End, Walsall 1-1 Leyton Orient