Sources close to the discussions said that Kraft Heinz's biggest backers - the US mogul Warren Buffett and 3G's Jorge Paulo Lemann - had been surprised by the ferocity of opposition to their advances from both Unilever and Westminster.
In crisis talks on Sunday morning, US time, the pair were forced to accept there was no chance they would succeed within the 28-day deadline imposed by UK takeover rules.
In an unusual move, the two Kraft Heinz and Unilever said jointly on Sunday evening that "Kraft Heinz has amicably agreed to withdraw its proposal for a combination of the two companies".
They added: "Unilever and Kraft Heinz hold each other in high regard. Kraft Heinz has the utmost respect for the culture, strategy and leadership of Unilever."
The cordial end contrasted with strong attacks by Unilever insiders when the bid was revealed. They condemned attacking Kraft Heinz's opportunism and argued its approach was evidence its cost-cutting efforts were "running out of gas".
Michael Mullen, a Kraft Heinz spokesman, blamed the company's abrupt withdrawl on the deal leaking "at an extremely early stage."
"Our intention was to proceed on a friendly basis, but it was made clear Unilever did not wish to pursue a transaction," he said. "It is best to step away early so both companies can focus on their own independent plans to generate value."
Paul Polman, chief executive of Unilever, had urged the company's largest shareholders to reject Kraft Heinz's advances, arguing that a takeover would destroy its long-term approach.
Unilever has roots in Victorian philanthropy with its history traced back to the Lever brothers, who developed Sunlight Soap "to make cleanliness commonplace; to lessen work for women; to foster health."
Since taking the helm in 2009, Mr Polman has been evangelical about corporate social responsibility setting the target of doubling revenues while halving its carbon footprint.
Since taking control of Heinz and Kraft in 2013 and 2015 respectively, 3G has meanwhile built a reputation as a savage cutter of costs and jobs.
Iain Wright, chairman of the business select committee, said its retreat from Unilever was "good news". "The two companies had really different cultures and it would have been hard to see how Unilever's viability would have continued under the cost-cutters", he added.
By walking away from takeover talks, Kraft Heinz is now barred from making a fresh approach for Unilever for another six months, although sources said that it was likely to receive "short-shrift" if it made another attempt.