Hull City failed to confirm their automatic promotion to the Premier League after losing 2-0 to Barnsley at Oakwell on Saturday.
The result means that only one point separates Hull and third-placed Watford as the league heads into the final round of fixtures.
Goals from Jacob Mellis and Chris O’Grady either side of half-time were enough for Barnsley, who moved out of the relegation zone with victory.
There was no such joy for Wolves, whose own relegation worries continued with a 2-1 home defeat to Burnley.
That result leaves Dean Saunders side needing a win on the last day away to Brighton, while hoping that results elsewhere go their way.
An eighth-minute goal from Greg Halford was enough to secure victory for play-off chasing Nottingham Forest at Millwall, moving them level on points with sixth-placed Bolton, who were held to a 1-1 draw by champions Cardiff City.
Brighton and Hove Albion booked their place in the play-offs, winning 2-1 against Leeds United at Elland Road.
Fourth-placed Crystal Palace were held to 1-1 draw away to Blackburn, while Middlesbrough drew 2-2 with Charlton.
And there were wins for Ipswich Town and Huddersfield Town, who beat Birmingham City and Bristol City respectively.