NAIROBI, Oct. 2 (Xinhua) -- Teammates and training partners Geoffrey Kamworor and Abel Kirui have both won the world marathon championships but there will be a wide rift between the two when they line up at the Chicago marathon on Sunday.

The two lead a battery of Kenyan road runners as they lay siege on the American city eyeing to improve on their personal best times and conquer the great Chicago course.

"It's just now down to days to the Chicago marathon and though we are friends with Geoffrey and teammates, each must strive to win the race," said Kirui, who will be running his third Chicago marathon after winning in 2016 and finishing second last year.

Kirui, a former Olympic silver medalist, has had a splendid marathon career since his debut in Berlin back in 2006 where he placed ninth in 2:17:47.

He has twice been crowned the world champion and also picked up wins in Vienna and Chicago.

Last year, Kirui returned to Chicago to defend his title but had to settle for second position, some 28 seconds behind winner American Galen Rupp.

In 2018, the 36-year-old Abel is back for his third successive appearance in the "Windy City", so what is it he loves about the event?

"I think there are a lot of factors," he says. "The course is very good and Chicago is just a clean environment with the race set in a beautiful city. I never feel any pressure in Chicago. I have had no injuries, which was totally different to last year, and I am very much hoping to be in the fight."

Kenya has always had a good performance in the men's race in Chicago. Save for last year, Kenyans have ruled the Chicago marathon course.

In 2013 former world record holder Dennis Kimetto was the champion. A year later, it was Olympic champion Eliud Kipchoge, who has gone on to set a new world record in Berlin at 2:01.39.

In 2015, it was Dickson Chumba who triumphed while in 2016, Kirui ruled the roost before Rupp disrupted the trend.

But the Kenyan runners are keen to restore their dominance in the race this year and are looking forward to fast time to cement their win.

Alongside Kirui, Kenya will also have Choge, Kenneth Kipkemoi, Stephen Sambu while Paris champion Paul Lonyangata has pulled out with an injury.