Barely a week since the fatal Boston Marathon bombings, the Kenyan distance running armada have set their sights on excelling at Sunday's London Marathon in what are arguably the toughest fields ever assembled.

The men's line-up reads like an Oscar list of distance running glitterati with the Kenyans and Ethiopian athletes being joined by surprise Ugandan Olympics gold medallist Stephen Kiprotich.

"It is time to focus on the race and forget about what happened on Monday. With the athletes entered, it will be a memorable run," the standard bearer in men's marathon running, Patrick Makau, the Frankfurt Marathon titleholder, said.

The 2:03:38 runner will go head-to-head with the man who fell only four seconds short of matching his world record only three weeks he had crafted it in the streets of Berlin in 2011, London defending champion Wilson Kipsang.

"This season, my aim is to defend my title and then after that, I can think of competing for my country again and making up for missing the Olympics gold medal," said Kipsang who won in 2:04:44 last year.

His return to London last summer as the overwhelming favorite saw him clinch bronze behind Kiprotich and world champion Abel Kirui, who is also in London in a bid to improve on his best ever finish there, fifth, in 2010.

"I have learned from my earlier mistakes and this time, I will give my best," the Berlin and Daegu Worlds winner stated as his aim for Sunday.

The field will be chasing the 2:04:40 London benchmark set by Emmanuel Mutai in 2011, and he is also in the explosive mix for Sunday.

Last year, Mutai, the 2010/2011 World Marathon Majors (WMM) champion endured a pale season by his standards, finishing seventh in his London defence before joining the Kenyan Olympics squad late in the day where he returned 17th.

His namesake and WMM crown successor Geoffrey Mutai, the 2:03:02 runner from the 2011 Boston Marathon, makes his London bow having won the Berlin Marathon last year.

G. Mutai as he is known has the ability to blow away the field as witnessed in his Annus Mirabilis of 2011 where he also set the New York Marathon course record of 2:05:06 and will be renewing his acquaintances with Makau whom beat him to second at the 2010 Rotterdam and Berlin marathons.

Stephen Biwott who recently set his 58:56 career best in finishing second at the lucrative Ras-Al-Khaimah Half Marathon in February comes to the race in fine fettle and is well capable of upsetting the cart.

Last year, he won the Paris Marathon in a lifetime best of 2:05:12 in April before finishing third (2:09:05) in his last outing over the ultimate distance in December at the Shanghai Marathon in China.

The late withdraw of three-time London winner, Martin Lel, who was the bridesmaid at both the 2011 and last year's races is the only blow to the Kenyan charge owing to his podium efficiency over the years secured mainly by his famed last kilometer sprint.

Tsegay Kedebe, the 2010 winner leads the Ethiopian challenge that also includes the gifted Feyisa Lilesa (2:04:52 PB) and Deressa Chimsa.

They will be seeking to sustain the momentum established by compatriot Lelisa Desisa who wrested back Boston honors from the Kenyans on Monday.

The corresponding women's race has seen Kenyan arsenal weakened by the high profile withdrawals of world champion, Edna Kiplagat, defending champion, Mary Keitany and last year's London fifth finisher, Lucy Kabuu.

That leaves Olympics and Worlds silver winner Priscah Jeptoo to take the fight to the field fronted by Ethiopia's Tiki Gelana, who forced her to accept the second medal in London last summer.

Florence Kiplagat, who was fourth last April, returns seeking her first honors and on her day, she has the power to obliterate her field as her 2011 Berlin Marathon victory in a career best 2:19:44 testifies.

Last year's Africa Cross Country winner Joyce Chepkirui's second bite at the London cherry after registering Did Not Finish last year is another interesting prospect having underlined her credentials by the 2012 Prague Marathon in a bristling 67:03.