Despite of arriving in the capital two days late, Japan's World Championships silver medallist Yoshimi Ozaki is hoping to race to a new lifetime best in this Sunday's Virgin London Marathon.

The 28-year-old, who moved into Japan's all-time top 10 with 2:23:30 to secure victory in the final edition of the Tokyo International Ladies Marathon in November 2008, hopes that her London debut will be a valuable experience.

"I'm here to go after my PB and if possible, to run 2:21," she said. "Coming into this week I've had heavy legs and I've been a little uneasy, but that feeling is getting better every day and I felt good on my run this morning. When I heard that we might not make the trip I was stressed but I realised I can still fit in my training so I'm not particularly worried anymore.

"London has always been the race that has brought together a mix of very good athletes and part of my reasoning for coming here is to gain more experience from battling it out in high quality race," she continued. "If I'm able to get a good result in this kind of field it will help improve my confidence going forward."

Ozaki, who was defeated into second place at the IAAF World Championships in Berlin in August 2009 by China's Bai Xue, has altered her preparation compared to previous marathons and concentrated primarily on speed training, along with increased mileage.

She lost out on the gold in Berlin when Bai pulled away from her in the last mile to win by just 10 seconds - the youngest ever women's world marathon champion at the age of 20.

With only three seconds between their best ever times, the World Championships medal duo could well be locked together again this weekend, but will their positions be reversed?

"This has all been a new experience and I won't know my real condition until I race," admitted Ozaki. "The increase in distance has been to develop my overall stamina but my coach is looking ahead to 2012 and wants to focus on my speed as well as overall strength."

She clocked a quick 70:06 in the All-Japan Corporate Half Marathon in March to guarantee her place on the Japanese team for the 2010 IAAF World Half Marathon Championships later this year

"I feel less pressure going into this weekend than I did going into the half marathon trial in Japan, but here in London I will be really testing myself. In the World Championships I just couldn't make that fast effort in the final stages. If I'm in the same position, I want to be able to do that on Sunday."