London - Kenya's Geoffrey Mutai has vowed to finally add the London Marathon title to his honours on Sunday, while three-time winner Paula Radcliffe prepares to bid a tearful farewell to the event.
Radcliffe's last appearance in the race that established her as one of the finest female marathon runners of all time will be the main focus for British fans.
But the battle for supremacy in the men's competition will provide a high-quality distraction from Radcliffe's emotional send-off.
Mutai has crossed the finish line in first place in the Boston, Berlin and New York Marathons, but he has been unable to emulate those triumphs on the streets of London.
In 2013 he dropped out with a hamstring problem at the 30km mark, while last year he was short of form and had to settle for sixth place.
To end his frustrating wait for a London victory, the 33-year-old will have to see off a star-studded field, including compatriots Wilson Kipsang, the defending London champion, and world record holder Dennis Kimetto.
"I have won in Boston, Berlin and New York, but the win I still want is this one," Mutai said.
"The fact that I have not done well here before is my main motivation now. It is what keeps me running and makes me want to come back.
"The London Marathon is more important to me now than the Olympics because it is more challenging. I will fight until my day comes."
With 2011 champion Emmanuel Mutai, 2014 runner-up Stanley Biwott, and 2014 Rotterdam and Chicago Marathon winner Eliud Kipchoge also on the start line, the race will feature the three quickest men in history and five of the all-time top 10.
Kipsang and Kimetto have never raced head-to-head before, and defending champion Kipsang, who set the London course record in two hours four minutes and 29 seconds last year, said: "I'm expecting a big challenge from Dennis.
"I've beaten him once and he's beaten me once. I have more experience in marathons but he has done very well in the few he's done."
Meanwhile, there won't be many dry eyes among Radcliffe's friends and family once her race is finally run over the same 26.1-mile route on which she set a world record of two hours 15 minutes 25 seconds in April 2003 - a mark which still stands.
The 41-year-old Englishwoman will compete not as part of the elite field, but among the mass ranks after battling a series of injuries in recent years.
Radcliffe's husband Gary, her parents and children Isla and Raphael will all line the course to watch the 2005 World Championship gold medallist bow out.
"I would love to have taken part in the London Olympics in 2012 as my last competitive race at the front but we don't get to choose that," said Radcliffe, who plans to continue running only in a non-competitive environment.
"I'm very lucky to have the long career that I've had. It's such a magical special race. It's something that's hard to put into words how important it is."
Radcliffe's record could come under threat from a quartet of Kenyan stars - Mary Keitany, the London champion in 2011 and 2012, defending champion Edna Kiplagat, Priscah Jeptoo, the 2013 winner, and Florence Kiplagat.
"Paula has been a great athlete and a great inspiration to women marathon runners," Edna Kiplagat said.
"We look up to what Paula has done, especially her solo world record, and that is what we are trying to go for on Sunday."
Also on Sunday the London course will play host to Switzerland's paralympic world marathon champion Manuela Schar, who aims to retain the global title she won two years ago in France.