Rovers came back from a goal down to get their Premier League Cup campaign off to the perfect start against Crystal Palace at Dulwich Hamlet's Champion Hill Stadium.
Joe Rankin-Costello bagged a late brace, tucking into an empty net and then rifling home to earn an opening three points for Billy Barr's boys in what was a scrappy encounter.
Harry Chapman equalised just before half time after Robert Street had given the hosts the lead midway through the first 45 minutes in south London.
Barr named five changes from the last outing at Derby County, with Isaac Whitehall, Sam Barnes, Hayden Carter, Lewis Thompson and John Buckley all coming back into the team.
Rovers began the game the stronger against their Professional Development League opponents, with Sam Woods heading a Chapman cross onto his own post before it bounced away 10 minutes into the encounter.
Despite Rovers' early dominance, Palace were awarded a penalty on 19 minutes after a foul in the box, but Flanagan slammed his spot kick against the base of Joe Hilton's right-hand post and the score remained 0-0.
But moments later The Eagles took the lead, with Flanagan involved in the move. The midfielder fed Robert Street, who rolled the returning Carter before finding the bottom left-hand corner.
But Rovers responded just a minute before the break through a looping header from Chapman. John Buckley picked out Lewis Thompson down the left flank and his cross was perfect for Chapman, who rose highest to nod in via the left-hand post.
That meant the two sides went into the break all square, which was probably fair on the balance of the play in south London.
Rankin-Costello went close to turning the score around just after the break, but his effort went inches past the post after he was played in.
At the other end, Street crashed a strike against the upright after a neat pass from Nya Kirby.
Jack Vale had the next opportunity with under 20 minutes remaining, but after finding the back of the net the Welshman was adjudged to be offside.
Vale had a glorious chance to put Rovers ahead soon after, but he skewed wide after being picked out by Whitehall, who was playing in an unfamiliar right back role.
But with 10 minutes remaining Rovers did get the winner, albeit against the run of play through Rankin-Costello.
After Dion Henry closed down Vale, the ball fell kindly for the midfielder, who slipped into an empty net from the edge of the box.
There was still time left for Rankin-Costello to make the game safe and that's what he did with two minutes remaining. He took a touch after getting on the end of a deep Buckley corner before smashing a half-volley beyond Henry and into the roof of the net.
Next up for Rovers in the competition is a home clash against Middlesbrough at Leyland on Friday 8th November, kick-off 7pm.
Crystal Palace Under-23s: Henry, D.Boateng, Woods, Tavares, Williams (Mensah, 46), M.Boateng, Lokilo, Kirby, Street, Flanagan (McGregor, 46), Pierrick.
Unused substitutes: Tupper, Steele, Ajayi.
Goal: Street 22
Booked: Williams, 15, Tavares, 34
Rovers: Hilton, Whitehall, Barnes, Carter, Thompson, Buckley (Paton, 90), Rankin-Costello (White, 90), Davenport, Mols, Chapman (Burns, 69), Vale.
Unused substitutes: Dowling.
Goals: Chapman, 44, Rankin-Costello, 80, 88
Booked: Rankin-Costello, 13, Buckley, 45