SAINT-ETIENNE, France — Alexander Kristoff of Norway, in a solo show of opportunistic racing, won the 12th stage of the Tour de France in a sprint as Vincenzo Nibali kept the yellow jersey for a 10th day on Thursday.

After hitching a ride behind the back wheel of Italian sprinter Matteo Trentin, Kristoff powered out of the barreling pack and beat Peter Sagan of Slovakia, who was second, by nearly a bike length, while Arnaud Demare of France was third. The pack overtook a pair of breakaway riders with less than 4.35 miles to go.

Kristoff, who won the Milan-San Remo race this year, pointed his fingers skyward and shouted as he crossed the line — pretty much without any of his Katusha teammates: Sagan’s Cannondale team and Giant-Shimano took turns leading the pack at the end. But Kristoff timed his burst perfectly.

“I won, finally, and I am really happy,” Kristoff said of his first Tour stage win, adding he had been second in two previous sprints. “It was time to win.

“In Norway, there was a lot of pressure on me: I am the only Norwegian this year!”

Kristoff paced himself without two big rivals: Giant-Shimano rider Marcel Kittel, who has won three stages, was dropped earlier in the ride along four small- and medium-sized climbs, while German countryman Andre Greipel, who won Stage 6, crashed within the last few miles.

The mostly flat 115.5-mile course from Bourg-en-Bresse to Saint-Etienne in southeastern France was well suited for a sprint finish.

The top standings didn’t change. Nibali leads Richie Porte of Australia by 2 minutes, 23 seconds, and Alejandro Valverde of Spain was third, 2:47 back.

American rider Andrew Talansky pulled out before the stage due to severe back pain from previous crashes.

AUSTIN, Texas — Lance Armstrong talked for seven hours with cycling investigators about doping in the sport’s past, said an attorney for the champion who was stripped of his seven Tour de France titles over his use of performance-enhancing drugs.

Armstrong attorney Elliot Peters said Armstrong set up the meeting and sat for questions for seven hours May 22 at a Washington, D.C., hotel.

“They asked him about everything. … If you made a list of all the questions people would want to ask about Lance and his activities in cycling and everything else, those were the questions that were asked and answered,” Peters said.