Chambers overcame false starts by both himself and Simeon Williamson to claim first place in 6.56secs and should secure the automatic berth for the World Indoor Championships in Valencia next month when the first wave of selections are announced tomorrow.

Craig Pickering had been expected to be his main challenger but the European Indoor silver medallist finished fifth and instead it was Williamson who was second in 6.61secs.

Assuming the selectors abide by their own criteria, they have little option but to pick 29-year-old Chambers.

UKA had already attempted to ban the athlete – who served a two-year suspension after testing positive for THG in August 2003 – from competing at the English Institute of Sport as they claimed he had retired to take up a career in American football, but he maintained this was not the case.

They then reluctantly agreed to accept Chambers could compete in Sheffield under International Association of Athletics Federations (IAAF) rules as he had constantly informed them of his whereabouts.

Chambers, though, insists he just wants to be able to do something positive for the sport.

He said: "Why would they want to stop me when I am trying to do something for them? I'm not trying to work against them, I'm here to put British athletics back on the map in a positive way.

"Yes, it's going through its ups and downs but I'm not here to create any nightmares. I'm here to put across a positive stance, help the youngsters be more inspired and do the best I can.

"I'm not the bad guy, I'm trying to be the good guy now."

The former junior 100m world record holder returned from his year's ban in summer 2006 and immediately impressed by running 10.07 in the 100m at Gateshead.

He then attended the trials for the European Championships in August, but was forced to pull out of the final of the individual event with a quad injury.

However, he was awarded the discretionary slot by the selectors – something unlikely to have been extended to him should he not have won today.

"I don't understand what the problem is," he continued. "I've made my mistake, everybody makes mistakes in life and what is important is that I made a mistake and now I'm trying to set a positive example.

Christian Malcolm, who finished fourth in the final, was stripped of the 4x100m title at the 2002 European Championships and the silver at the 2003 World Championships because of Chambers's drugs conviction.

However, he insists he holds no grudge towards his former team-mate.

"I've grown up with Dwain and known him since I was 14," he said.

"It's up to Dwain and the powers that be. It's nothing to do with me."