Only two of the three will definitely go up without resorting to the lottery of the playoffs, yet no points and just three goals separate them, with Middlesbrough due to host Brighton on the final day of the season.
The Seagulls had to overcome a battling performance from Charlton, and a bizarre beachball protest from the home supporters, to claim victory at the Valley on Saturday.
The game was held up for five minutes soon after the start as the balls were thrown on to the pitch in an escalation of recent fan protests against the owners of the relegated club.
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Sam Baldock, Jiri Skalak and Tomer Hemed scored for the visitors after Johann Gudmundsson had equalised in a game that brought further disruptions by home supporters.
Middlesbrough remained second on goal difference after failing to break Ipswich's resistance at the Riverside Stadium.
Hull and Derby County are already guaranteed playoff spots with Sheffield Wednesday, helped by Saturday's 1-1 draw at Derby, likely to secure the final berth.
Cardiff City, 2-1 winners over Bolton Wanderers, remain with a theoretical chance of pipping Wednesday and travel to Hillsborough next Saturday.
Hull reinforced their reputation as the division's most unpredictable team with a 2-2 home draw against Leeds United. Steve Bruce's side trailed, then scored twice in as many minutes before the interval before conceding a late goal to Stuart Dallas as Leeds secured a point.
MK Dons' relegation to League One was confirmed after just one season following their 4-1 defeat by Brentford. Nicky Maynard gave the Dons an early lead but Sergi Canos, on loan from Liverpool, Lasse Vibe, Ryan Woods and Jake Bidwell ensured that the Dons will follow Bolton and Charlton into League One next season.
Nottingham Forest beat Fulham 3-1 to secure their first victory at Craven Cottage since 1975.
(Editing by Ed Osmond)
