Tresor Kandol struck a first-half brace as Millwall moved up to second spot in the table with victory in a five-goal thriller at The Den.
Kandol got The Lions off to a perfect start after three minutes and then had Rovers reeling when he made it 2-0 with 17 minutes on the clock.
But Paul Trollope’s men reduced the arrears through Rickie Lambert (19mins), and although Gary Alexander (74mins) appeared to put the game beyond Rovers’ reach with a stunning third for Millwall, Jo Kuffour responded immediately to set up a nail-biting final 12 minutes.
It was hard to fathom how Rovers had yielded just one point from their last eight away matches, and they could count themselves unlucky not to have at least taken a share of the spoils from this pulsating clash.
It was non-stop from start to finish, but certainly not for the faint-hearted in an end-to-end encounter.
A few eyebrows were raised when the team line-ups were announced, with neither Lions boss Kenny Jackett nor his opposite number selecting a goalkeeper on the bench.
There were just three minutes on the clock when Rovers stopper Steve Phillips was picking the ball out of the back of his net.
Adam Bolder swung over a corner from the left, Phillips’ punched clearance was picked up by Tony Craig and although the defender’s initial effort was blocked, he squared the return to Kandol who swept the ball home from close range.
Lions keeper David Forde was called into action on 11 minutes, but spilled Chris Lines’ free-kick with David Martin hammering the ball clear.
Craig hit a first-time shot wide before Kandol looked to have put Millwall in control on 17 minutes, providing an exquisite finish from the tighest of angles after capitalising on a poor back-pass from Aaron Lescott.
But The Lions inexplicably took their foot off The Gas and when Stuart Campbell sent over Rovers’ first corner of the match barely 60 seconds later, League One top scorer Lambert stole in to head home his 18th goal of the campaign to make it 2-1.
Left-back Andy Frampton twice went close with headers from Craig deliveries, Kandol was crowded out as he prepared to shoot and then Grabban’s curling cross dropped just wide as Millwall pressed for a third.
Kandol was certainly more sinned against than sinning on 42 minutes when he was booked for failing to retreat at a free-kick - a bit difficult when you are a yard away having handed the ball to Rovers keeper Phillips, who then promptly kicked it straight at The Lions striker.
And referee Graham Scott - a late replacement for Pat Miller who was ill - then caused total confusion in first-half injury-time.
Jimmy Abdou committed a foul, only for Scott to brandish a yellow and then a red card, clearly mistaking him for Kandol who was yards away.
The Rovers bench appeared to think it was their frontman Lambert who had been dismissed, players from both teams surrounded the ref and, to his credit, Scott took the sensible option.
After consulting the fourth official, the referee rescinded the red card and booked Abdou, the correct decision.
Abdou didn’t appear at the start of the second-half, with Marc Laird stepping in to fill the midfield berth alongside Bolder.
The non-stop action of the opening half continued in the second and Kandol could have completed his hat-trick after 55 minutes.
A slick move involving Laird, Alexander and Grabban created an opening, only for Kandol’s shot-on-the-turn to be held by Phillips.
Back came Rovers and Lambert was denied by Forde, with a shot that the keeper knew nothing about as it bounced off his chest and over for a corner.
Forde did know all about a subsequent free-kick from Lambert after 66 minutes, and did well to get down low to push the ball away for a corner.
Chris Hackett replaced Grabban 60 seconds later and by 74 minutes, Millwall once again looked to have put enough daylight between them and Rovers with a third goal.
Paul Robinson’s raking pass picked out Alexander, he took two touches and hit an unstoppable rocket into the roof of the net from 16 yards.
Laird was denied his first goal of the season seconds later when his first-time shot saw Phillips produce the save of the match to somehow tip his 20-yarder away.
But Rovers were like a dog with a bone, and quite simply refused to give up the chase.
When The Lions made a hash of clearing their lines on 78 minutes, Kuffour turned smartly to reduce the arrears and set up a nail-biting finale.
The two teams traded chances; Hackett and Kandol for The Lions, Lambert and Disley for the visitors.
But unlike last season when Rovers twice caught Millwall out late on to snatch victory, there was to be no way back this time and Jackett’s men held on for their fifth win in six games.