Tears were shed as 13 friends of tragic runner Claire Squires ran past the spot where she collapsed in last year's London Marathon.
The 30-year-old, of Great Bowden, near Market Harborough, died near the end of the 26.2-mile course last year.
Ahead of the marathon, on Saturday night two of her friends – Lucy Marlow and Lisa Snare – laid flowers on the spot in Birdcage Walk, near St James's Park, London, where she collapsed.
It was a poignant reminder for the runners of the tragedy that overshadowed last year's London Marathon, just as the bombing of the Boston Marathon last week overshadowed this year's.
Suzie Munton, 38, of Market Harborough, was one of those running for Claire yesterday and finished in five hours and four minutes.
She said: "I cried all the way down Birdcage Walk.
"I wouldn't have run a marathon for many people but I was happy to be doing it for Claire Bear.
"It was really mental out there but with the amazing support you get running through the streets of London it's actually easier than training."
Lisa, 30, of Cambridge, said: "We got to London at 7.30pm on Saturday and we went to Birdcage Walk to lay some red flowers on the corner there.
"Me and Lucy wanted to do it for Claire. I wanted to run the marathon, too, but had an injury."
Mum-of-two Lucy, 38, also of Market Harborough, said the final mile was emotional.
Before beginning the marathon last year, Claire had asked Lucy to run with her in yesterday's event.
Lucy finished the run in five hours.
The friends set out to raise more than £3,000 for Squires Effect, an organisation set up in Claire's memory to help other charities.
They have already passed the £4,500 mark in memory of Claire, who died of heart failure.
Yesterday's marathon began with a 30-second silence among the 36,000 runners to remember the victims of the bombing of the Boston Marathon last week.
Three people were killed and more than 170 others injured by the twin blasts, close to the finish line of the marathon.
The attack led to heightened security at yesterday's event in London and runners and spectators showed their solidarity with the athletes and people in the crowd who were caught up in the Boston attack.
The runners yesterday were given black ribbons to wear over their hearts.
Vet Chris Sherwood was among the thousands of runners who put his hand to his heart as he crossed the finishing line.
Chris, 47, of Oadby, who raised cash for the PDSA animal charity where he works, said: "We wore black ribbons and as we crossed the finishing line we touched our hands to our hearts.
"The 30-second silence before the race was also perfectly observed. I'm always emotional at the start of a marathon anyway and I'm sure all the runners had the people of Boston in their minds throughout the silence.
"It was my ninth marathon and marathon running is all about celebrating life in a fun way and raising money for charity – basically all that's good in the world.
"For someone to decide to blow people up like that is undescribable."
Chris finished the marathon in three hours and 10 seconds and said he was "gutted" not to be 11 seconds faster.
"Some people were going to pay me more if I got less than three hours but I was going as fast as my little legs would carry me."
Loughborough MP Nicky Morgan, who ran the marathon for the first time, was also moved by the sense of empathy for the people of Boston.
She said: "All along the way there were signs about Boston and we were all very conscious of it."
The 40-year-old MP for Loughborough finished in just over five hours.
She said: "It was a relief to see the end and I'm not sure I'll be doing another marathon soon. After training in the snow it was actually a very warm spring day for the run so we all needed a lot more to drink than we were expecting."
Other runners included Kate McCann, who was running for the Missing People charity and is aiming to raise £20,000.
She completed the marathon in three hours and 56 minutes.
The men's race was won by Tsegaye Kebede, of Ethiopia, and the women's race was won by Kenyan runner Priscah Jeptoo.
