Romanian, Swiss, Ethiopian and Senegalese runners led the Tuesday competition at the World Athletics Championships in Edmonton, Alberta, Canada.
Romania's Gabriela Szabo out-sprinted her countrywoman, Violeta Szekely, to win the gold medal in the women's 1,500 meters. Szabo passed the favored Szekely in the final lap to take the gold medal in 4:00.57.
The bronze medal went to Natalya Gorelova of Russia.
Szabo is next scheduled to run in the 5,000 meters, but has threatened to pull out because her chief rival, Russian Olga Yegorova, has tested positive for drugs. Sazbo says she will decide later Wednesday whether to run. "I am so happy now, and I cannot make the decision now," she said. "I will go home and talk with my husband and my manager and make the decision, tomorrow."
Meanwhile, in the women's 400 meters, Senegal's Amy Mbacke Thiam won the gold medal by .002 second. The silver went to Lorraine Fenton of Jamaica. Mexico's Anna Guevra took the bronze.
Switzerland's Andre Bucher had a much more comfortable margin in the men's 800 meters, winning in 1:43.7. The Swiss runner was heavily favored to win and he says he used the pressure to prepare well for the race.
"I was looking forward to this World Championships," he said. "I was really nervous, of course, that I am running here. Actually I was thinking this morning that this is going to be a good day: I felt good and I am really happy to run and get that race over with as well.
The women's 10,000 meters title went to Derartu Tulu of Ethiopia, .004 of a second ahead of countrywoman Behrane Adere.
The women's hammer throw gold medal went to Yipsi Moreno of Cuba, with a toss of 70.65 meters. Olympic champion Olga Kuzenkova of Russia won the silver medal. The bronze went to Bronwyn Eagles of Australia.
Olympic silver medallist Fiona May of Italy won the women's long jump, with a leap of 7.2 meters. Russia's Tatyana Kotova won the silver, one centimeter back, with the bronze going to former champion Niurka Montolva of Spain.
The decathlon title went to Tomas Dvorak of the Czech Republic, with 8,902 points. Olympic champion Erki Nool of Estonia won the silver medal with 8,815, and Britain's Dean Macey took the bronze with 8,603 points.