The sky finally cleared at the world track and field championships Friday night. Even Mother Nature knows how special Yelena Isinbayeva is.

The 23-year-old Russian broke another pole vault world record, and the United States won two more gold medals as the competition entered its final weekend at Olympic Stadium.

The Americans fumbled away another potential gold with a dropped baton on their first handoff in the opening round of the men's 400-meter relay.

The United States increased its medal total to 20 -- 11 golds -- with 1-2 finishes in the men's 400 and women's 200.

Jeremy Wariner broke the 44-second barrier for the first time in his young but spectacular career, adding a world 400-meter title to his Olympic gold. The 21-year-old Texan ran the best race of his life in 43.93 seconds. Andrew Rock lunged ahead of Canada's Tyler Christopher at the line.

Olympic silver medalist Allyson Felix, the 19-year-old friend of double world gold medalist Justin Gatlin, pulled away down the stretch to win the 200 in 22.16. U.S. teammate Rachelle Boone-Smith edged Christine Arron of France for the silver. Both were timed at 22.31.

Gatlin, deprived of a shot at a third gold by the relay debacle, lifted Felix off the ground in celebration after the race.

"It was great," Gatlin said of her victory. "That's the biggest cheer I put out the whole time I've been here. Seeing her win the gold medal, she deserves it more than me. She worked so hard, she's been through so many coaches and so many ups and downs that a lot of people don't know."

Allen Johnson's bid for a fifth world title in the 110-meter hurdles failed when he knocked down six hurdles, including the last one, to finish third behind winner Ladji Doucoure of France and Olympic champion Liu Xiang of China.

After three days of wet, windy and cold weather, the sun came out Friday and only a brisk breeze kept conditions from being ideal. The women's pole vault had been postponed from Wednesday because of the nasty weather.

The delay provided a dry night for Isinbayeva to steal the show, clearing 16-feet 51/4 inches, a half-inch higher than when she broke the five-meter barrier (16-43/4) at the Crystal Palace meet July 22 in London. She has set the world record 18 times, indoors and out, nine times this year.

"No limit," she said after overcoming a pesky wind to clear the bar on her second try. "I don't believe I did it in this difficult weather. The stadium is wonderful and the crowd is good."

Isinbayeva is halfway to her goal of 36 world marks, one more than the great Sergei Bubka accomplished. The charismatic Russian looks like she has a good shot.

She started smiling before she hit the mat on her record vault, then raised her arms in triumph and did a back flip to celebrate. She posed in front of the sign that showed her record height, then wrapped the Russian flag around her, giving the television camera a coy grin.

"She's a personality, not only for sports," said Bubka, now an IAAF official. "She is very intelligent, and she's a star outside of sports."

Gatlin had talked about a world record in the 400-meter relay, but that dream died in a hurry.

Weary after eight races en route to his 100 and 200 golds, Gatlin was to run only in the finals.

But on the first exchange in the first heat of the qualifying, Leonard Scott barely got a hold of the baton from Mardy Scales, then dropped it. Maurice Greene, who was to run the anchor leg in his first appearance at the meet, could only watch from the far side of the track.

"I put all the blame on myself," Scott said. "I was trying to pull for it and it slipped out of my hand."

Yelena Isinbayeva clears 16-51/4, setting her ninth pole vault world record of the year. "She's a personality, not only for sports," Sergei Bubka said.