Youngsters put on their running shoes to complete a mile dash ahead of the full marathon tomorrow, the first under new ownership.
More than 1,000 children descended on Brighton's Preston Park this morning for the Mini Mile.
Spirits were high as they set off from the start line of the one-mile course.
The route took the runners, aged seven to 17, around the park, starting and finishing on the straight stretch parallel to London Road.
There were 11 races for different age groups. Each runner received a medal and awards were presented to the top three winners in each age group.
Among the winners was 14-year-old Alexander Cheeseman. He crossed the finish line in the first race of the event, for those in school Years 7 to 12, with a time of five minutes and 22 seconds.
Alexander, who goes to King's School in Hove, said: "It felt great to cross the finish line. I wasn't sure whether I was going to beat my time last year but I came first."
He is a part of the Brighton Phoenix running club. He added: "The training has been going quite well over the last few weeks, and it paid off today.
"The atmosphere was great."
His mother Kirsten said: "It was amazing to see him finish, he's worked so hard recently. He's totally motivated to get out and do it.
"He runs a few times a week on top of his school work, and he loves it which is good.
"I'm sure he will be running the full marathon soon."
Parents lined the route to cheer on the youngsters as they made their way around the park.
Mayor of Brighton and Hove Lizzie Deane sounded the air horn to start the first races of the day. She said: "It's brilliant to see so many young people taking part and having really good fun.
"The fact London Marathon has taken it on this year is great. I've noticed they're taking lots of care with the environment, for example, they are using recyclable plastic bottles."
She handed out medals to the youngsters after they completed the course.
The Brighton Mini Mile is the curtain-raiser for Brighton Marathon Weekend.
This was the first Mini Mile under the new management of London Marathon Events, which took over from Grounded Events in December last year.
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Event director Hugh Brasher was on the finish line of the Mini Mile.
He said: "We're absolutely delighted. The weather gods have really smiled on us today.
"Kids, smiling faces, and getting active is what this weekend is all about. It's about bringing together the community.
"The kids are the future of society, and getting them more active and inspiring them through events like this gives them a feeling they probably won't get normally."
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