Three goals inside the first 12 minutes of the second half saw Rovers turn on its head a cup tie they were being bossed out of.
Cambridge had looked in full command in their lead given by Luke Berry’s follow up from Barry Corr’s saved penalty.
Conor Grant equalised just after the break and before Cambridge could regroup, Mitchell Lund and Grant again put Rovers out of sight.
The game began at a frenetic pace, largely down to the approach of the hosts who looked to deny Rovers any time on the ball.
It was something they continued throughout the first half. Cambridge pressed with real ferocity, played one-touch short passes in the Rovers half and quick balls into the channels.
Rovers’ work rate and tempo under Darren Ferguson has been superb but they met a side whose intensity surpassed their own.
It was not that Rovers were particularly poor but they were left in a shell-shocked state by the hosts. They struggled to find any of the rhythm they have shown so far under Ferguson with Cambridge straight down their throats.
The hosts attacked in numbers and defended in the same fashion. The work of sitting midfielders Ryan Ledson and Conor Newton was key to this as they supported the attacking four as much as they did the back line.
When Rovers did attack, they were let down by ponderous play and poor passing. Both Andy Williams and Nathan Tyson were caught in possession on numerous occasions as they looked to craft opportunities.
Even after Rovers’ equaliser early in the second half, Cambridge were not knocked off their stride.
But by the end of the ten minute period which Grant’s first goal started, they were the side left shell-shocked.
Grant scored twice with strikes from outside the box, sandwiching a Lund goal which came down to sheer persistence.
Those ten minutes saw Rovers snatch command of the tie and latch on a grip they would never relinquish.
In terms of what had changed from Rovers’ approach as they turned the game on its head, it could only be said that they ceased being so ponderous in the final third.
Grant’s two strikes came from outside the box while Lund’s effort was crafted from an early cross by half time substitute. If you don’t buy a ticket, you don’t win the raffle.
Lund in particular was superb throughout the afternoon for Rovers. Recalled into the right wing back role in place of the injured Felipe Mattioni, he battled hard in defence in the first half and worked his socks off going forward.
Due to the pressure in the opening half, Lund spent most of his time beside the three central defenders and showed an excellent willingness to fight against some physically robust Cambridge play.
And his willingness to chase down apparent lost causes was key to Rovers’ first and second goals.
His performance suggests Rovers have a range of options at wing back perhaps previously unrecognised and eases fears they may be caught short if Mattioni does indeed return to Everton in January.
Cambridge should have been in front within the first few minutes when former Rotherham United and Barnsley men combined, Newton releasing Luke Berry into the box only for his shot to deflect wide.
And ex-Sheffield Wednesday striker Barry Corr should have done better with a free header he tamely put straight at Thorsten Stuckmann.
But Cambridge got the opening on 23 minutes. The Rovers defence were caught flat-footed with a ball over the top, allowing Berry to nip in. Both he and Aaron Taylor-Sinclair went for the ball with Berry tumbling and referee Mark Brown quickly pointing to the spot.
Corr’s spot kick was at the perfect height for Stuckmann but Berry darted in to meet the rebound and nodded into the far corner.
Cambridge were on top for much of the rest of the half, their workrate leaving Rovers struggling for a way into the game.
Ferguson sent on Stewart at the break in place of Tyson and Rovers equalised just two minutes into the second half.
Mitchell Lund showed excellent persistence to chase down James Coppinger’s cross-field pass and lay off to Grant who smashed low from 20 yards, the shot flashing under Beasant who was somewhat slow to get down.
Cambridge had the better period immediately following the equaliser, continuing in the same manner with which they played the first half.
But nine minutes after equalising, Rovers were in front.
Stewart worked space on the left and dinked in an in-swinging cross which looked to have evaded everyone until Lund slid in at the far post to poke the ball home.
Before anyone could catch their breath, Rovers extended their advantage inside a minute.
The ball was played back to Grant who struck first time, curling a wonderful effort from 25 yards which looped over Beasant and in off the far post.
Cambridge had the majority of the attacking play after falling behind but could not wrestle their way back into the game.
Substitute Liam Hughes twice hit the bar in the same attack as he headed off the woodwork from a corner before following up with the same.
After being so unsettled in the first half, Rovers could hardly have ended the second half in more comfortable fashion.
The magic lives on.
Cambridge: Beasant 6, Taylor 7, Roberts 7, Legge 7, Demetriou 7, Ledson 7 (L Hughes 79), Newton 8, Donaldson 6 (Simpson 70), Berry 8, Dunk 7, Corr 6. Subs not used: Dunn, Slew, Coulson, J Hughes, Jones.
Rovers: Stuckmann 6, Lund 9, Butler 6, Taylor-Sinclair 6, Alcock 6, Coppinger 6 (Keegan 67 7), Middleton 7, Grant 8, Evina 7, Williams 6, Tyson 6 (Stewart 46 7). Subs not used: Marosi, McCullough, J McKay, MacKenzie, Whitehouse.
Referee: Mark Brown (East Yorkshire)
Attendance: 3,951 (672 away)