Whisked to a private hospital by ambulance in a blaze of publicity, it emerged that the self-imposed incarceration would net the 30-year-old New Yorker more than 600,000.
Despite thousands of spectators gathering at Tower Bridge for the denouement of what has, at times, become something of a medieval freak show, the detractors and so-called Blaine baiters insisted that the stunt was an elaborate hoax.
His enemies have sought to keep him awake with foghorns and drums, and attacked the 7ft by 7ft by 3ft Perspex box with paint and rotten eggs. Women have mockingly bared their breasts, men their buttocks and last Monday, a woman ran naked underneath the man dubbed the "Hip Hop Houdini".
At the beginning of the stunt one man, armed with a four iron and a dozen golf balls, tried, and failed, to hit the magician from his tee-off point 60 yards away on the bridge ramparts.
Yesterday, however, doctors warned that Blaine - who weighed in at 11st 1lb, a full four stone lighter than when he started his incarceration - will need close medical care for the coming days.
Blaine cried as he left his Perspex prison and then told the assembled crowd: "This has been one of the most important experiences in my life. I’ve learned more in that little box than I have in years."
In recognition of the barrage of bananas and eggs thrown at him, he added: "I’ve learned how important it is to have a sense of humour and laugh at everything, because nothing makes sense any more. I love all of you forever."
Blaine was attended to by paramedics who placed him in a stretcher before he was taken to a waiting ambulance to be driven to a private hospital.
Some, however, believe that the water being fed to Blaine in a tube has been filled with nutrients to help battle starvation.
On the internet, those offended by the stunt, claiming it glorified starvation in a world where millions face a daily battle to feed themselves, have fought back. One site - www.wakedavid.co.uk - proclaims that it is "dedicated to keeping David Blaine awake for 44 days and nights", adding: "It’s not big, it’s not clever ... it’s a grown man in a plastic box."
One wag went much further by attaching a hamburger to a remote-controlled helicopter and flying it in front of the magician.
Friends, including the "spoon-bender" Uri Geller, yesterday, defended Blaine. He said: "Knowing David as a friend, this is not a trick or an illusion.
He is the ultimate entertainer and showman."
By the end of the fast, an estimated 250,000 had come to witness the spectacle which has been broadcast live by Sky One and in highlights by Channel 4.
Blaine’s reintroduction to food must now be managed carefully to avoid potentially serious problems, including sudden death from "re-feeding syndrome", while any hope of sexual relations with his glamorous German girlfriend, and ardent defender, Manon von Gerkan, could see his life cut short by an act of passion.
Conspiracy theories: were the public conned?
AMONG the more outlandish suggestions for how David Blaine may have pulled one over on the British public is the idea that the masses below his Perspex box are actually watching a holographic projection.
Given that the kind of technology only yet used in Star Trek is not available, other suggestions have been put forward.
One theory is that the water being supplied to Blaine is laced with nutrients, glucose and vitamins. The secure line to the box has attracted criticism, although tests carried out have revealed it is plain H2O.
The cherry picker which, late each night, rises to clean the transparent box has also been charged as a platform allowing the illusionist to escape.
Claims that a body double - seen with Blaine’s German girlfriend - has been spirited into the box each night, allowing the illusionist to slip off for a slap-up meal have been dismissed by his team.
Detractors also claim that the lip salve Blaine took into the box contained sugars and salt essential to maintain the body, or that he had a secret store of food under his, undoubtedly, dirty blanket.
Another suggestion, yesterday dismissed by Uri Geller, claimed that Blaine’s pillow was in fact composed of marshmallow.