Bending almost double in the last few strides, he held off the challenge of the 23-year-old US champion Reggie Torian to earn the only major title to have eluded him in his career other than the Olympic one.
That ambition still glimmers ahead for the Welshman, who appeared to be on a downward spiral out of the sport when he finished a dispirited fourth at the 1996 Atlanta Olympics.
But a combination of factors - including a renewal of his links with Arnold, a successful operation on an injured knee and a shedding of his responsibilities with Nuff Respect, the agency he founded with Linford Christie - has seen Jackson revive his career.
An unexpected silver medal at the 1997 World Championships showed he was still a contender, and last year he won a third successive European title.
Now, however, he has confirmed his return with a global title, the first claimed by a British athlete since Jonathan Edwards won the 1995 world triple jump title.
"I knew I had to win this," he said. "No messing about. There were no excuses, no injuries, no niggles. I had to win it for my head's sake and I'm really, really pleased I did what I expected of myself. It's a huge testing time when it's a mental, not a physical thing."
Jackson's winning time of 7.38sec was the fastest in the world this year, and only 0.08sec off the world record he set in 1994. Torian, who had led the world standings coming into this competition, was 0.02sec behind, with Falk Balzer of Germany taking bronze.
The Briton's concentration was tested to the limit by three false starts, the last of them down to him. But he was still able to go for broke when the race finally got under way, getting a superb start with a reaction time of 0.111sec - legal by just eleven hundredths of a second. In tennis terms, it was an ace on his second serve.
"Colin's a risk taker," said Arnold. "If you don't take risks, you won't win." Defeat, however, was something Jackson had refused to contemplate. "I don't want to sound arrogant, but I only came here to win. It was No 1 or nothing for me. It's important that Britain has a world champion once more - it's something the nation can brag about, and I'm pleased I kicked it off. We can win a few more in the next couple of days."
Torian was convinced that his own finish - twisting one shoulder forwards - should have brought him the title. "I am not congratulating him as a winner," he said. "I thought I won by at least half an arm." Jackson's face was blank at the post-race press conference as the American, sitting beside him, repeated his claim. "It was a very tight race, but I think I won it," he said. US team officials, however, did not bother to lodge an official protest after studying the photo-finish. It was a graceless performance from a man who, reportedly, aspires to becoming an actor.
But Jackson's satisfaction in a job well done was not spoiled by the protestations of the competitor he had expected to be his main rival here.
After suffering two defeats this season through what he believed to have been false starts, he had been comforted by the evidence that the recall equipment installed at these championships was being properly used. "Right from the beginning of the heats the officials were being very strict, and this helped me stay calm even after three false starts in the final."
After three silver medals in this event, Jackson had his gold. He plans to add another at this summer's outdoor World Championships in Seville, where Torian's fellow American Allen Johnson, who missed this weekend's competition because of injury, is expected to defend his title. "If I don't win in Seville then I will feel I have let myself down," Jackson said.
Earlier on the opening day of the seventh IAAF World Indoor Championships, Haile Gebrselassie, known to his many supporters as The Emperor, won the 3,000m title in a stadium that had just been vacated by Japan's own Emperor and the bulk of the spectators, most of whom were schoolchildren.
The Ethiopian, who was both bemused and amused by the virtual silence which greeted his efforts, was hoping to win another $50,000 (pounds 32,000) win-bonus in the final day's 1500m final. He conserved energy before producing a killing burst over the final 600 metres, which he covered in 85 seconds.
Nastja Rysich, of Germany, won the women's pole vault with 4.50m - Emma George, Australia's world record holder, pulled out with a hamstring injury after clearing 4.35m.
John Regis, fourth fastest in the world over 200m this year, made a disappointing first- round exit, failing to hold the bend of the track.