Report: women's marathon – Rio 2016 Olympic Games
She waited until the final three kilometres to make her decisive move, shaking off the challenge of two of the women who finished ahead of her in Beijing last year before going on to win in 2:24:04.
The pace was consistent from the outset as the field passed through 5km in 17:23 with most of the main protagonists visible at the front.
Portugal’s Sara Moreira, who had been carrying a slight injury going into the race, was one of the first casualties as she pulled up at 6.8km.
USA’s Desiree Linden moved to the front of the lead pack of 30 women just before 8km. By the next kilometre split, the pack had dwindled to just 13 women.
Kenyans Visiline Jepkesho, Helah Kiprop and Jemima Sumgong were in the lead pack along with the Ethiopian trio of Mare Dibaba, Tigist Tufa and Tirfe Tsegaye. The 10km checkpoint was reached in 34:22, exactly 2:25 pace.
Korean twins Kim Hye-Gyong and Kim Hye-Song were the next to drop off the pack, while Japan’s Kayoko Fukushi moved up through the field to join the leaders. After a quick segment between 5km and 10km, the pace settled again for the next 5km section and the lead pack grew to 16.
The first big development of the race happened just before 18km as Ethiopia’s Tufa, the 2015 London Marathon winner, suddenly stopped with what appeared to be cramp, leaving 13 women at the front.
Volha Mazuronak of Belarus was the next to show her hand and she moved to the front after about 18km. The lead pack at that point also included the two remaining Ethiopians, the full Kenyan contingent, the Bahraini duo of Eunice Kirwa and Rose Cheliimo, USA’s Shalane Flanagan, Linden and Amy Cragg, plus Fukushi and Peru’s Gladys Tejeda.
They reached 20km in 1:09:07 and half way in 1:12:56, which suggested a finishing time outside 2:25, but given the calibre of athletes at the front of the pack, there was every chance of a quicker second half.
Mazuronak was the first to put in a surge, which broke up the lead pack somewhat with Jepkesho falling behind. By 25km, reached in 1:26:07, the nine women at the front were exactly half a minute ahead of Linden.
With Mazuronak pushing the pace again, Cragg and world silver medallist Kiprop were the next to suffer. The pair drifted back with Linden catching them before the 30km marker, which the leaders passed in 1:43:21, some 13 seconds ahead of Linden.
The same seven women remained at the front through 35km, passed in 2:00:31, but Kirwa put her foot down at 36km in what proved to be the most decisive move of the entire race.
Within a matter of seconds, Kirwa, Dibaba and Sumgong had opened up a gap on Tsegaye and Mazuronak. It soon became clear that the medals would be go to the leading trio; the final 6km of running – which took runners around the Museum of Tomorrow – would decide the order of the medals.
With 2:15:00 on the clock, London Marathon champion Sumgong began her long drive for home. Kirwa was able to go with her, but Dibaba began to struggle and fell behind the leading duo.
As Sumgong turned the corner into the long straight heading towards the Sambodromo, she had a lead of about five seconds over Kirwa, who looked too tired to challenge.
Sumgong extended her lead all the way to the finish, crossing the line in 2:24:04 to become the first Kenyan woman in history to win the Olympic marathon title.
“I’m very grateful to win Kenya’s first gold medal in Rio,” said Sumgong, who had covered the second half in 1:11:08, almost two minutes quicker than the first half.
“It was very hot but everybody had to get through the heat. I had to control my body and listen to my body very carefully.
“I was in Beijing but I was pretty disappointed that I wasn't able to win a medal or make it on the podium, but I knew one time, one day, I would be somewhere,” she added. “I was never worried that I'd lose this. At the 40km I knew the gold was mine.
“I’m so happy, I feel extremely proud. I can't even explain what I'm feeling.”
Kirwa went one better than she did at last year’s World Championships, taking silver in 2:24:13 to earn Bahrain’s second ever Olympic medal in any sport. Dibaba also made her second successive global championships podium, running 2:24:30 to secure the bronze medal.
Tsegaye managed to hold off Mazuronak to take fourth place with the two women clocking 2:24:47 and 2:24:48 respectively.
Flanagan was next across the line in sixth in 2:25:26. US teammates Linden (2:26:08) and Cragg (2:28:25) also finished inside the top 10 as the finishing order from the US Olympic Trials was reversed.
Korean twins Kim Hye-Song and Kim Hye-Gyong were 10th and 11th respectively, both being given the same time of 2:28:36 as they crossed the line holding hands.
Latvia’s Jelena Prokopcuka (2:29:32), Italy’s Valeria Straneo (2:29:44) and Fukushi (2:29:53) also made it into the top 15 finishers.
Jon Mulkeen for the IAAF