Rovers Under-23s' four-game unbeaten run in league and cup came to an end at the hands of high-flying Chelsea Under-23s at the weekend.
Dan Butterworth scored again and played the full game against The Blues down in Cobham, but his strike wasn't enough against Andy Myers' side, who went top of the division with the victory.
There were few chances of note early in the game, with the closest Rovers coming to breaking the deadlock being when a Lewis Thompson centre evaded everyone in the box and the opportunity passing by.
It was the hosts who took the lead soon after, with Jon Russell putting Chelsea ahead just before the half hour mark. The midfielder was picked out in the box by Austrian youth international Thierno Ballo before firing past Joe Hilton and into the back of the net.
The visitors made a quick start to the second half and almost clawed a goal back through defender Hayden Carter who had a free shot at an open net following Karlo Ziger’s parry, but Marc Guehi raced back just in time to produce an impressive goal-line clearance to protect his team's lead.
More heroics were required in the danger area as Rovers pressed for an equaliser early into the second half in Surrey.
And Barr's boys managed to work a leveller that their play deserved with 14 minutes remaining. Buttworth struck a powerful effort into the top corner from six yards having latched on to a headed cross.
But a potential point turned into heading home with nothing to show for Rovers' efforts just two minutes later.
Substitute Armando Broja had only been on the pitch for 20 minutes, but it was the Albanian Under-21 international who produced the goods to restore Chelsea's lead.
The forward won the battle with his marker and charged through on goal before he coolly beat Hilton between the sticks to put the home side in front for the second time.
Croatian custodian Karlo Ziger remained alert in the late stages as Rovers searched for what would have been a late equaliser, most notably denying Ben Paton, who wriggled free at the near post.
That save was enough to put Chelsea back at the summit of the division, whilst Rovers dropped to eighth.
Barr's boys are back in action at Leyland on Friday night in the Premier League Cup, with a home encounter with Middlesbrough's Under-23s scheduled to kick-off at 7pm.
Chelsea: Ziger, Lamptey, Wakely, Guehi (c), Lavinier (Lawrence, 70), McEachran, Ballo, Mola, Brown, Russell (Broja, 56), Nunn (Lewis, 75).
Unused substitutes: Bergstrom, Simeu.
Goals: Russell 28, Broja 76.
Blackburn: Hilton, Whitehall, Thompson, Pike, Carter, Barnes, Mols (c), White, Burns (Zimba, 84), Butterworth, Paton.
Unused substitutes: Boyomo, Eastham, Durrant.
Goals: Butterworth 74.
Referee: Lee Collins.