The convict coach of Tyson Gay will get out of jail free tomorrow, to a new job, and a new life as coach to the hottest sprint property in athletics. He woke up this morning to discover that his American protege is World 100 metres champion, on training sessions he meticulously drafted in a notebook before he was sentenced to a year for fraud.

Lance Brauman will be freed into a halfway house, and an uncertain future with a wife and baby daughter to support. However Gay - who crushed world record holder Asafa Powell in Osaka last night, by imposing his will in the final 20 metres - intends to stand by him.

In restricted phone calls during his incarceration, the pair have discussed plans for Brauman and family to move to Florida, and continue coaching Gay and Veronica Campbell, who is fastest qualifier for the women's 100m semi finals.

The 25-year-old Gay won in 9.85 seconds into a headwind of half a metre per second. With the legal maximum of 2mps behind him, that time looks closer to 9.65. The world best is 9.77, twice recorded by Powell.

Last night, by his own admission, the Jamaican panicked when he sensed Gay on his shoulder. He appeared to quit, and his own cousin, Bahamian Derrick Atkins, caught him. Atkins set a national record of 9.91, with Powell third, in 9.96. Britain's Marlon Devonish was a disappointed sixth, in 10.14. Eight different nations were represented in a global sprint final for the first time.

Only Maurice Greene, winner in 1999 and 2001, ran faster (9.80 and 9.82) to win a world championship, but with kinder wind. Gay's best is 9.84, with a one-metre breeze behind him.

His mother, Daisy, met Gay at his hotel yesterday, and defused a crisis. She arrived with his step siblings, Seth, 9, and Haleigh, 11. "I was nervous," he confessed.

"I'd a lot of negative thoughts. I was wondering if people would still respect me if I lost. I didn't know if anyone would love me if I lost."

Mum inspired the race of his life, but he believes he can go faster. "I think I can break the world record this year, but I'm not focusing on that. This gold means a lot more to me than the world record," he told me.

Gay had phoned his coach in jail in Texarkana Correctional Institute yesterday. Brauman helped massage Gay's college grades at the University of Arkansas, so can't return there.

"I still look forward to working with my coach, and I'd like to dedicate this race to him," said Gay. "He's been through a lot. I spoke to Lance this morning. He told me to block out the other rounds, and focus on tonight. He told me that when he wakes up in the morning, he knows I'll be world champion. He told me to believe it. And that's what I did."

It was Powell's first defeat in any 100m race he had completed since the 2004 Olympics (excluding a defeat by drug-tainted Justin Gatlin, which is set to be annulled). "It wasn't a great race for me," he said. "I tightened up.

I panicked at the end, and Tyson got the best of me."

The post-race exchanges were were refreshingly devoid of posturing or hysteria. But so was Gatlin's demeanour when he won two years ago. He is now fighting a record eight-year ban.

Gay's secret is his finish. "When I get to 60m I try to hold it top-end speed longer than my opponents can . . . I've never ever had a great start, but I really believe in my finish."

Can he win the 200m?

It starts tomorrow, giving Brauman little time to investigate access to a TV.

Gay confirmed he can't leave the US. "The plan now is to get some rest, some massaging and icing, and get through the first couple of rounds as easy as possible," said Gay. "Other guys are going to be pretty much fresh."

Devonish, at 31, was the only survivor of Britain's Athens Olympic gold-medal relay squad in the final. In 2004, he was ranked No.162 in the world, behind no less than 46 Americans. Only one American lined up beside him last night.

The 24-year-old Mark Lewis-Francis, still to match the 10.04 he clocked aged 19, missed the final by a hundredth of a second, timed at 10.19 in his fourth World Championships. Craig Pickering, just 20, was sixth behind Powell in their semi, with 10.29.

Despite their sprint pedigree, the US is not the team Britain should fear in the relay. It is Jamaica. The Caribbean fast-twitch maestros had three in the semis. So did Britain. The US had just Gay.

Kim Collins, the defending champion from St Kitts and Nevis, went out with 10.21. Collins was one of eight semi-finalists from the Caribbean, while Matic Osovnikar, of Slovenia, who was seventh, is the first Caucasian to reach a world final in 20 years.