Wigan reached the FA Cup final for the first time as they recorded a 2-0 victory against the backdrop of disgraceful scenes of violence from some Millwall fans at Wembley.
Goals from Shaun Maloney and Callum McManaman either side of the interval were enough to seal a meeting with either Manchester City or Chelsea for Wigan.
But Wigan's ecstasy was scarred by the repeated eruptions of fighting among the Millwall supporters, which left some fans bloodied and younger ones crying at the ugliness of it all.
On the pitch, there was no doubting the Latics were the more cultured outfit and, in Maloney, had the game's stand-out player. That said, Millwall made a solid contribution to an enterprising opening and James Henry dragged a shot wide from a decent position and Danny Shittu attempted an ambitious free-kick from 35 yards that screwed wide.
It was Maloney who got the momentous match-winner when Latics beat Manchester United for the first time last season, and he was at it again on Saturday. Arouna Kone created the problem, with a neat turn just inside the Millwall half, followed by a bustling run that attracted too many defenders. Maloney intelligently dropped into space, which the Ivorian found him in, allowing the Scot to sweep home from eight yards.
Either side, McManaman was denied by two excellent saves from David Forde. At the other end, the recalled Ali Al Habsi had to deal with pressure and presence rather than actual shots. Even when James Henry created room for himself inside the box and prepared to pull the trigger, Jordi Gomez was on hand to nick the ball away from him.
Another brilliant piece of play from McManaman five minutes after the restart should have sealed the game. Checking inside, the winger sent two defenders sliding out of play, but his shot curled narrowly over.
Millwall attempted to make the most of their reprieve and only a last-ditch intervention from Paul Scharner denied Andy Keogh a shooting opportunity, before the Austrian got the final touch to a Mark Beevers effort that bounced narrowly over.
But the Championship outfit were let down by members of their own support, whose scuffles among themselves left a sour taste, especially with small children in the vicinity.
It was not long before the scoreline was looking ugly too as Gomez slid an excellent pass through for McManaman. The youngster kept his nerve to round Forde before slipping the ball into an empty net.