The World Championships opened here with Kenya's defending champion Edna Ngeringwony Kiplagat claiming the first gold in the women's marathon and Britain's double Olympic champion Mo Farah triumphing in style in the men's 10,000m race.
The 33-year-old Kiplagat, who led home a clean Kenyan podium sweep in 2011 Daegu, made history as the first woman ever to win back-to-back marathon titles in World Championships, defending her title in 2:25.44 Saturday, reports Xinhua.
"I am delighted I was able to defend my title successfully. The time of the race is unusual because I am used to running most of my races in the morning. So during my preparation I tried to adjust my training to the time," said Kiplagat.
Italy's Valeria Straneo, who led for most of the race, took silver in 2:25:58. Kayoko Fukushi of Japan was third in 2:27:45.
"I think that I am the surprise of the day. To me this medal is a big surprise. I never thought that I would win the silver here," said the 37-year-old Straneo.
Straneo took the lead early in the race and finished the first 5 km in 17 minutes and seven seconds, pacing a leading group of 13 runners. After 33 km the leading pack was trimmed to only two runners with Straneo still leading and Kiplagat on her heels.
Straneo managed to maintain her lead till the 40 km mark but could not stop the defending champion to take the lead in the final kilometres.
"At 40 km I had to let Edna go because I felt a pain in my legs. I ran my own race from the beginning and my pace was good," said Straneo.
Britain's double Olympic champion Mohamed Farah claimed the men's 10,000m title. It was a sweet revenge for Farah who was beaten by a 52.8-second last lap by Ethiopian Ibrahim Jeilan at the 2011 Daegu Worlds.
Farah kept a low profile at the start, staying last in the first three laps. He dashed to take the lead after the sixth lap before immediately slowing down to hide himself in the middle of the chasing group.
The 30-year-old, gold medallist in men's 5,000m and 10,000m at the 2012 London Games, sped up to seize the lead again with two laps to go and held off a homestretch charge from defending champion Jeilan to win the 25-lap race in 27 minutes and 21.71 seconds.
"It was a great race and I respected all my competitors. Jeilan won the gold in the last World Championships. I am not dominating long distance; what I want is only to collect more medals for my family and my country," said Farah.
"I had the experience from a couple of years ago and I saw Jeilan coming at the bell. I didn't want to lose again. I remember a couple of years ago I was second and I was just digging in and make sure I didn't over stride. I kept looking across and you could see in my eyes, I was just making sure they didn't come after me. It was nice to come out here and win it," he added.
Jeilan, who missed almost all of last year and didn't compete in London, finished second in 27:22.23 while Kenya's Paul Kipngetich Tanui finished third in 27:22.61.
Olympic champion and world record holder Ashton Eaton of the United States led the men's Decathlon with 4502 points after five events.
The evening session witnessed first round competition of men's 100m sprint with Jamaica's world recorder holder Usain Bolt running a relaxing 10.07 seconds to finish first in the seventh heat.
United States sprinter Mike Rodgers topped the timesheets in 9.98 while China's Zhang Peimeng equalled his own national record of 10.04 to win heat four.
