NAIROBI, March 29 (Xinhua) -- Kenya's Geoffrey Kirui can throw down the gauntlet at the Boston marathon on April 16 knowing that his challengers for the World Marathon Majors (WMM) will be hot on his heels in London a week later.

Kirui is targeting his second win in Boston after storming to victory last April in a time of 2:09:37. He won 150,000 U.S. dollars in prize money. "I'm happy to return to Boston to defend my title. I had to end my holiday early to start training and I do not regret it. I am getting in top shape ahead of the race," Kirui said on Thursday.

Kirui will return to defend his title against spirited challenges from Ethiopia's Abdi Nageeye and Kenyan Philemon Rono. The Kenyan became the first man to win the Boston Marathon and World Championships in the same year.

This month top runners including Olympic Champion Eliud Kipchoge, Abel Kirui, Kenenisa Bekele and Dickson Chumba all seek to topple the leader. Kipchoge, Kirui (Abel) and Bekele will be running in London on April 22.

The Boston Marathon is part of the WMM, the premiere series of marathon races which includes road races in Berlin, Boston, Chicago, London, New York, and Tokyo plus the Olympic Games and IAAF World Championships marathons.

In the women's race in Boston, Kenya's Edna Kiplagat will seek to win her second title. Unlike Kirui, Kiplagat could only get silver in the World Championships last year after dominating in Boston.

"I look forward to the challenge in April of once again racing against the world's best athletes," said Kiplagat.?