The four-horse race was reduced to three on Saturday as Aston Villa's 3-1 defeat at Manchester City ended their chances, while Liverpool, who host Chelsea on Sunday, are now the longest of outsiders.
Tottenham's 1-0 home win over Bolton Wanderers kept them in the box seat on 67 points, one ahead of City to set up what should be a tumultuous night at Eastlands on Wednesday when the two sides meet in their penultimate game.
A win for Spurs would seal fourth but any other result would mean the decision going to Sunday when Tottenham visit relegated Burnley and City are at West Ham United.
Villa, with one game at home to Blackburn Rovers left, are on 64. Liverpool, seventh on 62, end away to Hull City.
Fourth place ensures only a place in the qualifying round of the Champions League and, as Everton found when they crashed the big four party five years ago only to go out to Villarreal at the first hurdle, a tough game can await.
However, should Spurs or City make it into the big time it could transform either club.
City, since their takeover, do not exactly need the money but they do need the kudos if they are to attract the truly top-ranked players who can help them take the next step.
Spurs would also find more agents knocking on their door as the dual attraction of the Champions League and a London lifestyle would no longer restrict top-class overseas interest to Chelsea and Arsenal.
Spurs finished fifth in 2006 and 2007 but their current total of 67 points has already surpassed both those seasons and is their best in the Premier League.
"I think anyone would think seriously about coming to this club anyway but the Champions League would help attract players," Spurs manager Harry Redknapp told BBC Radio 5-Live after Tom Huddlestone's superb shot had beaten Bolton.
While Spurs really want to nab fourth, City really need to.
Their Arab owners did not pump in their millions to secure a July trip to Lithuania in the Europa League - they expect an immediate return for their investment.
"We have a "final" on Wednesday," City manager Roberto Mancini said.
"It's probably the most important game for the club in the last 10 years."
With Liverpool needing that match to be a draw combined with defeats for both protagonists in their final games and two wins for themselves to snatch fourth, they can already start planning for a Europa League return.
Villa too are out of it after failing to put enough pressure on City after John Carew had put them ahead on Saturday as a Carlos Tevez penalty and goals from Emmanuel Adebayor and, in the last minute, Craig Bellamy, settled it.
"We've finished sixth in the last two years, on 60 points and 62 points. We've got more points this season (64) and up until last week 63 points wasn't even guaranteeing seventh in the league," said Villa manager Martin O'Neill.
"Manchester City and Tottenham have become very strong, it's a very strong league.
