Rovers fell behind after 24 seconds and never recovered as they were beaten at Northampton Town.
Matt Crooks fired home an incredibly early effort for a lively Northampton side buoyed by the arrival of new manager Jimmy Floyd Hasselbaink.
It took until the second half for Rovers to really get going but, try as they might, they simply could not break down the Northampton door and slipped to their second defeat of the season.
Darren Ferguson made three changes to the side that drew with Peterborough the previous weekend.
James Coppinger, Alfie May and Niall Mason all dropped to the bench with Harry Toffolo making his Rovers debut, Rodney Kongolo handed his league debut and Liam Mandeville returning to the side.
The start to the game could not have been worse for Rovers as they fell behind with less than half a minute gone.
George Smith was given far too much space on the left and ghosted into the box before cutting a pass back for Crooks who slammed in first time from ten yards.
Tommy Rowe went close with a deflected effort soon after but Rovers struggled to settle into the game.
Northampton were happy to let them have the ball in certain areas of the pitch but began an intense press whenever Rovers had the ball in their back line.
It made for a nervy defence which regularly misplaced passes and missed tackles in the face of pressure from an energetic Northampton side.
There was a lengthy break in play when assistant referee Danny Gratton pulled up injured and was forced off, with Ferguson taking the opportunity to deliver some strongly-worded instructions to his players.
And Rovers improved in the middle period of the half and crafted a fine opportunity. Kongolo slid in a pass for Matty Blair who flashed a ball across the face of goal which John Marquis just could not reach. Mopping up the loose ball, Tyler Garratt shot but it deflected into an easy save for Matt Ingram.
The improvement however was short-lived as Rovers struggled. Play was either too ponderous or too rash and both made life easy for the hosts.
Northampton should have doubled their advantage as half time approached. Alex Revell nipped in to cut out a misplaced pass from Joe Wright and fed Crooks who could only fire wide.
And Crooks really ought to have added a second before the break when ghosting in behind Garratt to meet Revell's cross with a diving header but again sent the ball wide.
Coppinger was sent on at the start of the second half and helped spark a good deal of improvement from Rovers.
They had much more impetus and much more intent as they swarmed forward in numbers.
But they just could not find the opening they needed.
There was a shout for a penalty when Marquis looked to have been pushed by Aaron Pierre, attempting to meet a high ball.
Joe Wright looped a header onto the roof of the net from an excellent ball by Rowe.
Ferguson threw on Jordan Houghton and Alfie May in a double substitution and Rovers continued to push forward.
May soon saw a shot on the turn deflected wide when Marquis squared to him at close range.
And Rowe brought a decent save from Ingram when he flicked on a corner at the near post with the Northampton keeper parrying at the top corner.
Coppinger drilled a low effort from 25 yards which Ingram parried and the Northampton defence mopped up with Marquis lurking.
The best chance came in the last minute of normal time when Ben Whiteman smashed a piledriver from 20 yards which Ingram tipped over with a superb save.
Rovers continued to push but could not break through. Coppinger saw a long range strike loop off a defender only for Ingram to claim.
Northampton: Ingram, Moloney, Taylor, Pierre, Buchanan, Grimes, Crooks (Richards 77), McWilliams, Smith (Powell 88), Revell, Long (Waters 57). Subs not used: Cornell, Barnett, Poole, Kasim.
Rovers: Lawlor, Wright, Butler, Garratt (Houghton 60), Blair, Kongolo, Whiteman, Rowe, Toffolo (Coppinger 46), Marquis, Mandeville (May 60). Subs not used: Marosi, Alcock, Mason, Williams.
Referee: Darren Handley (Lancashire)
Attendance: 5,843 (736)