Lee Merrien will run in the 2012 Olympic marathon after selectors reversed a decision not to pick him.
The 32-year-old, from Guernsey, failed to run under the 'A' qualifying time of 2:12 at but was the first British finisher in a personal best time of 2:13:41.
UK Athletics initially threw out Merrien's appeal.
But the selectors were allowed to reconsider their decision and Merrien has been added to the Team GB squad.
Merrien was forced to run the 'A' standard after he failed to finish in the top 20 at last year's World Championships and Scott Overall ran under 2:12 in last year's Chicago Marathon.
"Following consideration of all relevant facts and using its expert opinion, (UK Athletics) exercised its discretion to nominate Lee Merrien to the BOA," UK Athletics said in a statement.
Merrien told BBC Guernsey: "I'm ecstatic, it's something I'd waited for for such a long time and to know that it's going to happen now is very special.
"Technically, under the grounds of the appeal process, I didn't have any grounds to appeal, but they decided that my performance in the race at the weekend did warrant selection."
Merrien said he felt a mixture of emotions after the London Marathon, with a personal best and being the first British finisher overshadowed by missing out on the Olympics by 101 seconds.
"If it had been any other year I'd have been really pleased to be first Briton and to run a personal best," he added.
"I should have been happy, but I didn't achieve what I was after but it was a mixture of emotions."
Merrien's plight was the with almost 3,000 people signing up to a Facebook page calling for GB selectors to reconsider their decision.