LONDON – Allyson Felix finally won an individual Olympic gold medal, gliding home with her effortless stride to take the 200 meters and end the stranglehold of Veronica Campbell-Brown on the event. Aries Merritt added to the perfect sprint night for the United States, dominating the 110-meter hurdles final ahead of compatriot Jason Richardson. Behind them, Cuba's Dayron Robles, the 2008 champion, was smashing a hurdle in frustration after he pulled up lame with a right hamstring injury halfway through the race. In the heats, China's Liu Xiang, the 2004 champion, also pulled out injured. And making for a golden hour for the United States, Brittney Reese added the long jump title soon afterward to complete a triple for the Americans. In a biggest race, loaded with gold medalists, American Felix was quickest out of the blocks, and once she had her smooth, elegant stride going, none of the power racers on her inside could come close. Shelly-Ann Fraser-Pryce of Jamaica added silver to her 100 gold medal and Carmelita Jeter took bronze. Campbell-Brown faded out of contention down the stretch and finished fourth, failing — just like pole vaulter Yelena Isinbayeva did the night before — to become the first woman in track and field to win three gold medals in the same individual event at three consecutive Olympics. Sanya Richards-Ross, who was seeking a 200-400 double, fell back into fifth place. It was a thrilling US victory in the Jamaica-US sprint rivalry. By the looks of it, though, Jamaica should prevail again in the men's 200 Thursday. Usain Bolt is one victory away from becoming the first man to repeat as double Olympic sprint champion and reaching his ambition of becoming a “living legend” after he qualified for the 200 meter final. This time, too, everything is set for a direct duel with his training partner Yohan Blake, the silver medalist in the 100. Wallace Spearmon was the only American through to the final, and France's Christophe Lemaitre also advanced. Russian Natalya Antyukh secured the women's 400m hurdles gold medal when she dug deep to hold off American Lashinda Demus. Antyukh clocked a personal best of 52.70 seconds. World champion Demus (52.77) tried valiantly to close in the final strides with Czech Zuzana Hejnova taking bronze in 53.38. Robert Harting won the men's discus with a throw of 68.27 meters to give Germany its first gold in athletics and first in the discipline for 16 years. The 27-year-old edged out Ehsan Hadadi, who won Iran's first ever Olympic medal in athletics with a throw of 68.18m and had led until the penultimate round. Defending champion Gerd Kanter of Estonia was third with a season's best of 68.03m. In the morning, there was notable interest in the women's 800m heats where Sarah Attar became the first female track and field athlete to represent Saudi Arabia at an Olympics. The 19-year-old received a generous ovation as she trailed in last of the eight runners. Attar, who clocked two minutes 44.95 seconds – over 43 seconds behind heat winner Janeth Jepkosgei Busienei of Kenya – is the second Saudi woman to compete at the Games following judoka Wojdan Shahrkani. “It is the higest honor to be here to represent the women of Saudi Arabia,” said Attar. “It is an historic moment. I hope it will make a difference. It is a huge step forward. It's a really incredible experience.” Defending champion Pamela Jelimo of Kenya and South Africa's former world champion Caster Semenya eased into Thursday's semifinals. Olympic 10,000 meters champion Mo Farah again rode a wave of fervent home support, cranking his aching legs back into life to reach the 5,000 final as decathlon world record holder Ashton Eaton began his gold bid in impressive style. Farah capped a golden night of track and field for Britain Saturday with a memorable victory and was afforded a huge ovation on his return to the Olympic stadium, again packed to the rafters for the morning session. The Somali-born runner is bidding to join an illustrious group to secure the long-distance double at a Games, including Emil Zatopek (1952), Lasse Viren (1972 and 1976), Miruts Yifter (1980) and Kenenisa Bekele (2008). Farah qualified third from the first of two heats but it was far from plain sailing for the 29-year-old. American Eaton came into these Games as one of the hottest favorites for gold having broken Roman Sebrle's 11-year decathlon world record at the US trials in June, setting a new mark of 9,039 points. Eaton, 24, the 2011 world silver medallist, holds a 105-point lead over compatriot and world champion Trey Hardee after the opening three events, helped by a lifetime best throw of 15.48 meters in the shot. There was bitter disappointment for 37-year-old Czech Sebrle, the 2004 Olympic champion, whose participation in his fourth and final Games lasted just one event.— Agencies