The 34-year-old, who races Usain Bolt in Ostrava next weekend, is free to qualify for the Games after the British Olympic Association removed a by-law giving drug cheats automatic lifetime Olympic bans.
Chambers, who finished runner-up to American sprinter Wallace Spearmon in the 150m straight race, admitted he was nervous of the reception awaiting him but was left delighted.
“If I said that I wasn’t worried about how the crowd would greet me, I’d be lying,” said Chambers, whose 100m split-time of 10.26 seconds was just short of the UK Olympic qualifying time.
“It was on my mind, which is natural. I’m going to be optimistic and expect it to carry on in a stadium atmosphere, but that’s about how I conduct myself and how I perform.
“I never thought that this chance will come again. I’d resigned in my mind to thinking that whatever happens, happens and I’ll just continue to do the best in my career while I can.
“But now things have turned around and I’m very fortunate and very grateful for that – to get the chance to appear in front of a British crowd and that’s something I’ve wanted to do for a long time.
“I’ve still got to hit qualifying time to make all this hard work justified so I’ll get myself prepared for Ostrava and the relay in Rome and then it’s pretty much countdown to the trials.”
Chambers was in a playful mood at the starting line, and believes a weight was lifted off his shoulders when he was given the all-clear to attempt Olympic qualification.
But the former world indoor champion is not expecting there to be an immediate impact on his chances of establishing himself as one of the best in the world.
He said: “I think there’s a load off my shoulders and the momentum is definitely changing. My mind is a lot more at ease now, and that was one of the many things that was making it difficult to perform.
“Because of the situation at the time, I had things to deal with, but now I’ve got a free mind and concentrate on enjoying it.
“A lot of people said you must be over the moon about the decision, but, honestly, I’m exhausted.
“For something that’s taken nine years to be a reality, I can’t expect it to be resolved in two weeks.
“I’m still on the rollercoaster, trying to find my feet and getting prepared for competitions that I never expected to get. But now I’ve got them, I feel like a little kid again. I’ll just get back to the raw basics of running.”
British winners on the day included Christian Malcolm, who beat fellow Team GB hopeful Mark Lewis-Francis in the men’s 100m event, while Andy Turner put a disappointing last place in the 110m hurdles behind him to win the 200m straight hurdles.
Montell Douglas claimed a creditable second in the women’s 150m straight, while James Ellington came second in the men’s 200m straight event.
Pole vault hopeful Holly Bleasdale was disappointed with her second place, finishing behind Germany's Lisa Rysich.