After a goalless first half in which Orient had the edge, the game came to life with a goal glut after the interval when the lead changed hands three times.
It looked ominous for Doncaster at the start as Orient seemed sharper and big striker Jabo Ibehre caused problems for the home defence.
But they managed to withstand the threats although home keeper Neil Sullivan had to make a fine save when Ibehre almost caught him unawares with an angled 25-yarder just before the interval.
An inspired second-half substitution by Rovers boss Sean O'Driscoll helped to turn the game. He sent on Jason Price in place of Sean McDaid and the Welshman had an immediate impact.
Price latched onto the ball after a free-kick from Gareth Roberts had ricocheted off the defensive wall, and he nipped in to break the deadlock in the 52nd minute.
Orient showed their mettle when they hit back to equalise four minutes later with Adam Chambers supplying Ibehre to fire home from close range following slipshod play by the home defence.
The O's turned the tables in the 68th minute when they went ahead themselves with skipper Stephen Purches squeezing a shot past Sullivan from the narrowest of angles to stun the home side's fans into silence.
But they were cheering a minute later when Price put Rovers level again after turning on a sixpence to slam home a pass from Lewis Guy.
James Hayter showed remarkable reflexes when he hooked home after a shot from Paul Green had bounced off Stuart Nelson.
Richie Wellens added the fourth to seal the issue two minutes from time in fine style after working a clever move with James O'Connor which stretched the visitors defence.