Rovers slipped to a second straight league defeat, going down 3-1 at home to Doncaster Rovers.
Individual errors proved costly, as goals from John Marquis, James Coppinger and substitute Alfie May saw the Yorkshire side secure the points at Ewood Park.
After a lacklustre first half, where neither goalkeeper was unduly troubled, the visitors broke the deadlock less than a minute after the restart.
Elliott Ward was the guilty party, as his miscontrol allowed Marquis to run in on goal and he successfully stroked the ball into the bottom corner.
Doncaster then doubled their lead midway through the second half. Charlie Mulgrew was adjudged to have brought down Coppinger in the box and the Donny captain picked himself up to score from the spot.
David Raya then made a superb save to deny Doncaster a third, before Ian Lawlor produced an even better piece of goalkeeping to keep out Ben Gladwin's goal-bound effort.
However, with eight minutes remaining, the visitors extended their lead further. Raya failed to clear his lines and May had the simple task of slotting the ball into the empty net.
Rovers did pull a goal back late on when Dominic Samuel scored his second goal in as many games - heading home Ryan Nyambe's cross - but it proved to be too little too late.
Ahead of the game, Tony Mowbray made two changes to the side that defeated Coventry City in the Carabao Cup on Tuesday night.
Danny Graham and Peter Whittingham returned to the starting line-up, with Liam Feeney and Samuel dropping to the bench.
Captain Mulgrew recovered from the knock that forced him off at the Ricoh Arena, whilst Bradley Dack was named amongst the substitutes after recovering from a hamstring strain.
There was still no place in the 18 for Craig Conway, who is on his way back from injury, or new signing Marcus Antonsson, who only joined the club 24 hours ago.
Doncaster stuck with the same side that drew 0-0 with Gillingham on the opening day - making three changes to the side that knocked out Bradford City in midweek.
Rovers enjoyed plenty of possession early on, but they had to wait until the midway point in the first half for the game's first real opening.
Corry Evans won a brave header in midfield, which sent Graham racing towards a retreating Doncaster defence. Whittingham was in acres of space to his right, but Graham opted to go it alone and saw his shot blocked.
Doncaster threatened at the other end soon after as a cross from the right found Marquis, whose goal-bound shot deflected just past the post off Nyambe.
Paul Caddis forced the first save of the game on 33 minutes, but his tame left-foot shot rolled comfortably into the keeper's arms.
A minute later, Marquis again set his sights, but fired high and wide of the upright.
On 39 minutes, Whittingham's floated free-kick was punched only as far as Richie Smallwood, whose first-time volleyed defelcted just wide for a corner.
An uneventful first half ended with Evans dragging a shot wide of the far post from the edge of the area.
The game sprung into life less than 60 seconds after the restart, in calamitous circumstances. Mulgrew played the ball back to Ward, whose miscontrol allowed Marquis to race through on goal and he finished confidently past Raya.
Caddis blazed over the bar on 56 minutes and that would prove to be his last involvement as Rovers made a double change, with summer signings Dack and Samuel both introduced.
Fellow new recruit Gladwin came on for his home debut soon after.
However, it was the visitors who doubled their advantage moments later. Mulgrew was adjudged to have brought down Coppinger inside the box and, despite a lack of appeals, the referee pointed to the spot. Coppinger stepped up himself and coolly slotted the ball straight down the middle of Raya's goal.
On 69 minutes, Raya made a superb save to prevent Rovers from going three goals down, as he got down low to his left to tip Tommy Rowe's long-distance drive around the post.
Whilst that save was impressive, Lawlor's at the other end was even better. Gladwin opened up his body and looked to curl an effort into the top corner, but Lawlor pulled off a sensational save to tip the ball over the bar.
Coppinger then struck a free-kick into the side-netting, before Doncaster did grab a third. From a long ball forward, Raya came racing off his line to clear, but he headed the ball straight into the path of May, who slotted the ball into the empty net.
Rovers grabbed a consolation effort late on, when Samuel notched his second Rovers goal in as many games - heading home Nyambe's right-wing cross - but it did little to appease the expectant Ewood crowd.
The final chance of the game went the way of the visitors, as May raced through on goal in added time, but he dragged his shot wide of the far post.
Rovers have a week to lick their wounds ahead of a trip to Bradford next weekened, where they will be looking to pick up their first points of the new campaign.
ROVERS: Raya, Caddis (Dack 57), Nyambe, Ward, Mulgrew (c), Williams (Gladwin 65), Smallwood, Evans, Whittingham (Samuel 57), Bennett, Graham.
Subs not used: Leutwiler (GK), Doyle, Feeney, Chapman.
Goal: Samuel (87)
Booked: Mulgrew, Evans
DONCASTER: Lawler, Andrew, Butler, Mason, Marquis, Rowe, Whiteman, Mandevielle (May 63), Wright, Blair, Coppinger (Kongolo 83).
Subs not used: Marosi (GK), Alcock, Williams, Garratt, Ben Khemis.
Goals: Marquis (46), Coppinger (pen 67), May (82)