Saint-Denis, France ? The United States started slowly at the track and field World Championships, then became mired in controversy. But the Americans flourished Sunday, sweeping three relays to finish first in medals.

The U.S. squad struck gold in the men’s 400- and 1,600-meter relays, and a gutsy anchor leg by 18-year-old Sanya Richards gave the Americans a win in the women’s 1,600 relay.

Americans took home 20 medals, 10 of them gold, to lead all nations in the nine-day meet. Next was Russia with 19 medals, including six golds.

This was the first time in a decade the Americans reached 20 medals.

Richards, a sophomore at Texas who became a U.S. citizen last year, held off Russia’s Natalya Nazarova and Jamaica’s Lorraine Fenton down the stretch to give the U.S. women victory in the 1,600 relay.

“I love running anchor. I always run anchor,” Richards said. “I’m actually more comfortable running anchor, so I was happy to be there and I was happy to bring it home for the U.S.”

Jerome Young, who won the 400 title Tuesday and then became enveloped by a 4-year-old drug case, barely held off France’s Marc Raquil to give the U.S. men the 1,600 relay title.

“I just didn’t worry about it,” Young said of the controversy. “I just put it behind me and kept on going, and just basically used that as a motivation.”

Even without 100 world-record holder Tim Montgomery and three-time 100 world champion Maurice Greene, the men’s 400 relay team took gold for the third straight World Championships when J.J. Johnson caught Britain’s Dwain Chambers in the final few meters.

After a poor baton pass from Bernard Williams to Darvis Patton, Johnson was in third place when he began the anchor leg. First he caught Brazil’s Claudio Roberto Souza, then leaned at the finish to edge Chambers and give the Americans the victory in 38.06 seconds.

Montgomery left the meet after a fifth-place finish in the 100, though he had not been expected to run on the relay squad in any case. Greene, who usually runs the anchor leg for the U.S. team, hurt his left leg in the 100 semifinals.

“I felt a lot of pressure because a lot of people thought we couldn’t win without Maurice or Tim,” Williams said. “It shows America is deep, with a good number of sprinters.”

There was some controversy. Kelli White passed a drug test after winning the 200 meters but still could lose her two gold medals from the worlds, officials said Sunday.

The results from the second test were revealed one day after officials from the International Association of Athletics Federations said White had tested positive following her victory in the 100.

White won gold in the 100 a week ago and completed the sprint double in the 200 Thursday, becoming the first American woman to sweep both events at a world championships.

Even though White tested clean after the 200, the IAAF said her positive test after the 100 would be enough to cost her both medals.