Dominic Samuel and Harry Chapman both scored twice, as Rovers Under-23s came back from 3-1 down to defeat 10-man Brighton 5-3 at the Amex.
Goals from Max Sanders and Taylor Richards saw the hosts lead 2-0, before Chapman halved the deficit in fine style on the stroke of half-time.
Bojan Radulovic restored Brighton's two-goal advantage on 53 minutes, before Seagulls skipper Sanders was given his marching orders moments later.
A quickfire double from Samuel, who was making just his second appearance after 12 months out injured, drew Rovers level, before Sam Barnes headed the visitors in front and Chapman completed the comeback in added time.
Ahead of the game, Billy Barr made three changes to the side that lost 2-1 to Wolves last time out, as Barnes, Andy Jackson and Louie Annesley came in for Joe Grayson, as well as suspended duo Matty Platt and Charley Doyle.
The new-look back four got off to the worst possible start, conceding inside four minutes when Sanders curled a superb shot into the right-hand corner from outside the area.
Rovers responded well, with Brad Lyons playing in Samuel, who saw a shot deflect just wide, whilst Barnes twice went close with headers at the back post and Chapman curled an effort over the upright after a neat one-two with Stefan Mols.
However, on 37 minutes, Brighton doubled their lead when Radulovic got in behind the Rovers defence and he squared the ball for Richards to tap home.
Joe Hilton then made a smart save to deny the lively Ryan Longman from adding a third, before Chapman reduced the arrears with virtually the last kick of the half, dancing past the Brighton defence before coolly slotting the ball in off the far post.
Rovers made an attacking change at the break, bringing on Luke Brennan for Lewis Thompson, but it was Brighton who scored the next goal - Longman getting to the byline, before delivering a pin-point cross for Radulovic to head home.
The hosts were then reduced to 10 men, as Sanders was shown his second yellow card in quick succession for a foul on Tom White and Rovers made the Seagulls pay.
On 57 minutes, Brennan played the ball into the feet of Samuel, who spun superbly, before firing a lovely left-foot shot into the top right corner of the Brighton net.
Four minutes later and Samuel scored his second. White did well down the right and he centred for Samuel to tap home.
The Rovers striker came close to his hat-trick on 66 minutes as Brennan crossed from the left, but Samuel's downward header went just past the post.
The visitors were completely in control by this point and it seemed only a matter of time before they went in front - and the goal duly arrived on 81 minutes.
A corner was played short to White and his cross was powerfully headed home by Barnes.
A man down, Brighton rarely threatened in the closing stages and ultimately it was Rovers who rounded off an eventful evening with the eighth goal of the night.
In the fifth minute of added time, Chapman latched onto a ball over the top and he cleverly lobbed Tom McGill to seal Rovers' first three points of the Premier League 2 season.
Brighton: McGill, Cochrane, A. Davies, Roberts, Cox, Sanders, Baluta (Yapi 60), Longman, J. Davies, Richards (Gwargis 65), Radulovic (Tilley 77).
Subs not used: Desbois, Freestone.
Goals: Sanders (4), Richards (37), Radulovic (53).
Booked: J. Davies, Baluta, Sanders.
Sent off: Sanders.
Rovers: Hilton, Jackson (Whitehall 58), Barnes, Annesley, Thompson (Brennan 46), Chapman, White, Lyons, Hart, Mols, Samuel (Burns 82).
Subs not used: Eastham.
Goals: Chapman (45+3, 90+5), Samuel (57, 61), Barnes (81).
Booked: Samuel, Barnes, Jackson, Mols, Hart.