NAIROBI, Sept. 12 (Xinhua) -- Long distance runners Noah Kiptoo Kiprotich and Sammy Kitwara hold the key to breaking of the world record at the Berlin marathon on Sunday.

While the two are likely not to finish the race in their roles as pacesetters for their clients New York Marathon silver medalist Wilson Kipsang and Olympic champion Eliud Kipchoge cannot be overlooked.

Both Kipsang and Kipchoge will make attempts to break the 2:02:57 world record set by Kenyan Dennis Kimetto on the same course back in 2014.

Speaking in Nairobi Wednesday prior to their departure to Berlin, Kiprotich, 29, said his work is to run up to 31km and leave his elder brother Kipsang to carry on.

"I will be looking forward to a good race where I want to help my brother lower the course record, which is the world record. We have been hunting it for some time now," said Kiprotich.

On the other hand, Kitwara, 32, who will pace-run Kipchoge says they have gone through all the requirements and he is focused on doing his job.

He also believes despite the high pace he will run in the first 35 kilometers, he dreams of finishing the race.

"The work is simple, lead Kipchoge up to the 35km mark. Kipchoge has clear target, he is going for the world record, but remember he will not be running against the clock alone, but a very tough field which includes Kipsang and Eritrea's Zersenay Tadese. They are strong runners, whom I have competed against

"It will be a tough race. Eliud is going there to run for a world record. Forget anything else said, if the conditions are good, the world record is coming down," said Kitwara.

Kipsang held the world record for one year when he broke it in 2013 clocking an impressive 2:03:23 to eclipse the 2:03:38, which had been posted by compatriot Patrick Makau.

It was the only race that Eliud Kipchoge has ever lost since he turned to marathon in 2013. Kipchoge finished second. However, Kimetto improved the mark to become the first man to run under two hours and three minutes.

He clocked the current mark of 2:02:57 in 2014, which has remained in force till today.

Last year, Kipchoge attempted to break the record on his third time running in Berlin but poor weather, rainy and windy conditions prevented him. He clocked 2:03:32.

"Kipchoge would have broken it last year because I was the one who paced him. The conditions were too hostile - it was too rainy and windy. We hope for the best this time. We have planned to pass the halfway mark at by 61:15 to 61:20 minutes. He is hoping to run a world record of 2:02:40 or thereabouts," he said.

On the other hand, Kipsang has predicted the record will be lowered down to 2:02:50.

Since his debut in the event in Hamburg in 2013, Kipchoge has won every marathon from Chicago (2014), Berlin (2015 and 2017) London (2015, 2016 and 2018) and Rio Olympic marathon.

His current personal best time is 2:03:05, which he set when winning London race in 2016.