The Spurs were not prepared to increase their valuation of £ 25m on the midfielder, 22, when Aston Villa demanded £ 40m.
But they trusted that the inhabitants of Midlands, in financial crisis at that moment, after not being able to gain the ascent, would eventually fall apart.
Even Villa's boss, Steve Bruce, feared losing the game creator Grealish.
But as the Spurs remained convinced that the deal would pass before the transfer deadline last Thursday for the Premier League signings, the game change was Villa's sudden change of ownership.
Tony Xia sold his majority stake in the club to two billionaires in the Egyptian Nassef Sawiris and the American Wes Edens, who bought 55 percent of the club for 30 million pounds sterling.
The new Villa regime not only rejected Tottenham's eventual offer of £ 25m, but also insisted that Grealish was not for sale.
The midfielder was determined to move to Mauricio Pochettino's squad, but now Villa is more interested in negotiating a new deal.
Grealish has two years left of his contract.
Meanwhile, the head of Villa Bruce will tour the banks of the Premier League while looking to boost his squad of the Championship with the loan signings.
Clubs outside the top category have until the end of the month to add high-level players temporarily.
Chelsea forward Tammy Abraham, West Ham winger Robert Snodgrass, who spent last season on loan at Villa Park, and Yannick Bolasie, expelled from Everton, are among Bruce's targets.