MK Dons suffered their first defeat in four games as Kazenga LuaLua inspired Brighton at a wet Withdean Stadium.
LuaLua, returning to Brighton on loan from Newcastle United, smashed the opener with a spectacular free-kick shortly after half-time, before setting up Glenn Murray for a second 15 minutes from the end. It was the result the Dons will find hard to argue with, the Seagulls having fashioned the far better of the chances in both periods, and one that drops them into mid-table after five games played.
But with Wednesday's game in hand against out-of-sorts Southampton on the horizon, Karl Robinson's side could quickly re-establish themselves among League 1's front runners. They simply found LuaLua,19-year-old brother of former Portsmouth striker Lomana, too hot to handle in East Sussex - the Congolese winger providing a tough test for every defender he came up against all afternoon.
Making his first start since returning to the Withdean Stadium, LuaLua immediately looked Brighton's most likely source of an opening, teasing Danny Woodards down the left flank with devilish intent. Murray made a mess of the Congolese winger's first two crosses, unable to connect with the first one and stabbing the second round the post inside the first six minutes.
The first half's outstanding contributor, LuaLua was a bundle of energy, defying a spell of play that had otherwise lacked tempo. The Dons were trying to establish a foothold by keeping the ball and Brighton were looking for LuaLua at every opportunity. Peter Leven saw a long-range free-kick headed off target by Radostin Kishishev, but Dons chances were at a serious premium as Tommy Elphick and Adam El Abd brutally repelled their advances.
LuaLua was at it again on 33 minutes, finding a way to the byline down the left before drilling a ball across that Murray somehow failed to turn home from close quarters. It had been a wasteful half for the former Rochdale striker, and he continued in the same vein six minutes later - heading Inigo Calderon's cross over after Sean O'Hanlon's slip had allowed him to rise unmarked.
Mathias Kouo-Doumbé saw a header from Leven's free-kick deflect into the arms of Casper Ankergren, but the visitors were probably happy to reach the break with parity. But that parity was ruthlessly shattered four minutes into the second period, typically by LuaLua.
Though, on the face of it, the winger's well-struck free-kick flew straight over the head of David Martin, the Dons 'keeper was clearly deceived by a dipping swerving strike that was hit like a hammer. LuaLua made the most of it, somersaulting with delight at his crackerjack opener. Robinson's side foraged for a response - stand-in skipper Jermaine Easter just unable to convert after Woodards had headed down a Didi Hamann free-kick. But even the familiar changes of Lewis Guy and Jabo Ibehre off the bench were unable to stir them sufficiently to break Brighton down.
The Seagulls, by contrast, had the explosive ability of LuaLua to turn to and after the wide-man saw penalty appeals waved away following Luke Chadwick challenge inside the box, he conjured the goal to put the game beyond doubt 15 minutes from time.
Woodards was left dangerously exposed in a one-on-one with the Magpies loanee and was unable to prevent his raid inside. The cross was chipped out of Martin's reach and Murray provided the finish with a diving close-range header. It was a lead Brighton always looked comfortable with, taking their foot off the gas in the game's closing stages and affording the Dons time to search for a way back into it.
Jemal Johnson, re-introduced to the first squad in recent weeks, was afforded an introduction off the bench, but the Dons' probing was fruitless as the hosts kept them at arm's length.
Brighton (4-4-2): Ankergren; Calderon (c), Elphick, El-Abd, Painter; Bennett, Sparrow (Dicker 64), Kishishev (Bridcutt 90), LuaLua (Smith 87); Murray, Barnes.
Subs not used: Brezovan, Baz, Hart, Taricco.
Goals: LuaLua 59, Murray 75
Booked: Murray, Sparrow, LuaLua, El Abd
MK Dons (4-4-2): Martin; Woodards, O'Hanlon, Kouo-Doumbé, Chicksen (Johnson 82); Balanta, Hamann (Guy 60), Leven, Chadwick; Easter, Baldock (Ibehre 60).
Subs not used: Carrington, Searle, Flanagan, Powell. Booked: Hamann, Leven
Attendance: 6683 (274 away)
Referee: Phil Gibbs (West Midlands)