MINSK, Belarus (AP) — Sarah Hammer of the United States grabbed her sixth career gold medal and second of the week by winning the women's omnium Sunday, while Rebecca Angharad James of Britain made history by winning the women's keirin at the track cycling world championships.

It was the second gold medal in as many days for James, and her fourth medal in five days.

Stefan Botticher won the men's sprint title for his second gold, while France dominated the men's Medison 50K race.

James became the first British woman to win four medals at one championships. She took bronze medals in the women's 500-meter time trial and team sprint and added gold in the sprint on Saturday to crown her triumph with a win in the keirin race.

James led from the start and edged Gong Jinjie of China by 0.116 seconds. Lisandra Guerra Rogriguez of Cuba was 0.121 seconds back in third.

"I can't believe it ... That final was so hard. Just to come away with a gold medal is just unbelievable," James said. "Just the adrenaline got me through it today. I had a pretty good sleep last night. I woke up this morning and I didn't feel that tired. It's the last day of racing and I just wanted to get everything out of the tank here."

James wrapped herself in a British flag and crossed the track to embrace her parents in the stands.

"In the final I just got every single little bit out of the tank," she added. "I'm coming away with the gold."

Kristina Vogel of Germany crashed on the last turn as she tried to challenge the pack.

Hammer, who won the individual pursuit on Wednesday, scored 20 points in the overall omnium standings after six events, four points less than defending world champion Laura Trott of Britain, who beat the American for the Olympic gold in the discipline in London. Olympic bronze medallist Annette Edmondson of Australia had 26 points for third.

In omnium, points are awarded in reverse order so the rider finishing with the fewest points wins.

Botticher beat Russia's Denis Dmitriev in two races in the sprint final to claim his second gold medal this week. Francois Pervis of France edged Sam Webster of New Zealand to win his second bronze medal and third in five days.

The American rider had a six-point advantage over Trott going into the final 500-meter time trial event and clocked the sixth result. Trott was timed fourth to narrow the gap by two points.

Hammer wept with joy after the race and then picked up an American flag and rode with it over her head around the track at Minsk Arena.

"It's unbelievable. It just doesn't feel real to me right now," Hammer said." I always had it (victory) in the back of my mind, but to be honest I was aiming to be in the top eight in all the events, and to qualify first, it gave me a bit of confidence. But in omnium you never know it till it's over. I knew I had the legs to be up first, but actually, to be the world champion — this is crazy."

Hammer was the only rider representing the United States at the championships.

"It (result) couldn't have been better. I'm so excited," Hammer said.

Botticher outmaneuvered Dmitriev tactically in both races, forcing him to go ahead, while the German powered from behind with half of the lap left to edge the Russian at the finish line.

"It's a great and amazing feeling to win a sprint title," Botticher said. He also won gold in the team sprint earlier this week.

The French team of Vivien Brisse and Morgan Kneisky won three of the 10 sprints in the 50-kilometer, 200-lap race to claim the title ahead of Spain and Germany.

British riders won nine medals at the championships — five golds, two silvers and two bronze. Germany was second with 8 (3-3-2), followed by Australia with 2-2-4.