Little-known Moses Kosgei and Georgina Rono on Sunday upset the odds at the second edition of First Lady half marathon in Nairobi.
James Mwangi and Rosemary Wanjiru also blew away a star-studded field to wear the 10km crown under baking weather conditions at the Nyayo National Stadium.
But it was particularly sweet victory for Kosgei and Rono who looked rather green in the star-studded field as they lined up in the competition slightly below the radar proved they were no pushovers as they struck titles in the 21km races.
They produced a superlative showing to wow the huge crowds –among President Uhuru Kenyatta, Deputy William Ruto, First Lady Margaret Kenyatta, Ruto's wife Rael, cabinet secretaries, envoys and other dignitaries –at the race, which First Lady Margaret Kenyatta's Beyond Zero campaign.
Kosgei, who trains in Iten, formed the leading pack of 11 runners which had world-beating runners including two-time world marathon champion Abel Kirui and former world junior 5,000m silver medalist Mathew Kisorio.
The lithe Kosgei then produced a sudden burst of speed that reduced the field to shreds on the final kilometre, breezing the tape in 61 minutes and 28 seconds.
Kosgei, 23, said: "The race was quite challenging given the hilly sections of the course. I never expected to win here but I have made it. I am now setting my focus on big races abroad, though I have not settled on one."
But Kisorio, who competed in New York Marathon 2011, said he is keen on the domestic races at the moment. Andrew Kimutai, another newcomer, came second in 61.35 as Kisorio (61.53) and Alfred Kimeli (61.59) followed.
Peter Emase (62.04), Isaac Kipkoech (62.09) and Declark Omari (62.12) returned fifth, sixth and seventh respectively. Nelfhat Sirma (62.17), Albert Kangogo (62.23) and Henry Kiplagat (62.29) sealed the top-ten spots.
Georgina Rono, who has a 2:21.58 personal best she set in Frankfurt Marathon in 2012, stunned the women's classy line up. She stormed into the lead at mid-way even as her challengers kept close tabs.
She then sped away with her arms pumping and went through the first lap half (10.5km) in a swift 33.36. Rono firmly controlled the race even as her challengers Mercy Kibarus and Caroline, the 2011 Boston Marathon winner, breathed down her neck.
That could not disorient her as she stepped up the pace in the final stages of race that spread out all his rivals, opening a sizeable gap at the finish line in 64.05.
Kilel exchanged the lead with Kibarus, fourth at the IAAF world half marathon in Copenhagen, Denmark, last year and then charged back with a super-finish to go past the flagging Mercy Chemutai, who drifted back to fourth place.
Rono won in 64.05 ahead of Kibarus (68.13), Kilel (68.23) and Mercy Chemutai (68.42). Rosemary Wanjiru (30:28.4) led former Olympic Youth 3,000m champion Gladys Chesir (30:35.0) and Anne Wanjiru (30:40.0) in the 10km race. James Mwangi (29:03.2) and Emmanuel Ngatuny (29:05.4) topped the men's race.