Cardiff are on the brink of ending their 51-year wait for promotion to the English top flight, now known as the Premier League, after Rudy Gestede's double helped clinch a 3-0 win over 10-man Nottingham Forest.
A draw against Charlton on Wednesday will be enough to secure the Welsh club's promotion to the Premier League.
Hull are on course to join Cardiff among the elite after Robert Koren's late winner sealed a 2-1 win at Ipswich.
Victory for the Tigers lifts them six points clear of Watford in the race for automatic promotion.
Watford may have to settle for a spot in the play-offs after their surprise loss at struggling Peterborough.
Brighton got their play-off push back on track as they ended a three-match winless run with a comfortable 2-0 victory at Middlesbrough.
Bolton moved into the play-off places for the first time this season after Craig Davies's late penalty earned a win at bottom of the table Bristol City.
The All Whites striker Chris Wood's Leicester City drew again, 2-2 with visitors Birmingham City, to extend their winless run to nine games - but Leicester are still just two points outside the playoffs zone in eighth.