Olympics-Alpine skiing-Shiffrin risks all for slalom gold

* Shiffrin wins gold as youngest slalom champion * Teenager risks all on second run * Veteran Marlies Schild takes silver for Austria (Adds quotes, detail) By Alan Baldwin ROSA KHUTOR, Russia, Feb 21 (Reuters) - U.S. teenager Mikaela Shiffrin won slalom gold on Friday with a heartstopping second run on the ragged edge that sent her into the Olympic record books as the youngest champion in the discipline. Shiffrin, 18 years and 345 days old but already a world champion, was fastest in the first leg but risked all on the second by pushing too hard under the Rosa Khutor floodlights. The Vail, Colorado, resident's outside ski lifted into the night air as she fought for balance before regaining full control. "Sometimes Mikaela, for some reason when she's really hammering it, gets a little in the back seat," said a relieved coach Roland Pfeifer, who for one awful moment feared the gold had gone. "She's overdoing it, she skis a little bit too hard, shooting out all of a sudden. She overdid it in the second run and that was brutal. "I can't describe how I felt. I thought 'It's over'. But luckily she was really ripping the top of it (the piste) and it was just good enough to win," he told reporters in the finish area. Austria's Marlies Schild, who would have been the oldest slalom champion at 32, took silver - just as she did in Vancouver four years ago - with compatriot Kathrin Zettel settling for bronze. Germany's Maria Hoefl-Riesch, the 2010 champion bidding to become the first woman to win back-to-back slalom titles, finished fourth after being in second place at the end of the first run. Slovenia's Tina Maze, chasing her third gold medal of the Games after her success in downhill and giant slalom, slipped from a medal position to eighth. Schild's sister Bernadette, fourth after the first run with Marlies sixth, hooked a gate on the second trip down the slope and went out. "It's a big shame when you are this close to a medal," said the younger Schild. "Of course I'm really happy for my sister but I knew she had nothing to lose after her first run and if what she planned to do worked out she would be super-fast." Shiffrin's second leg was a marked contrast to the first in which she looked controlled and confident. "She skied perfectly like she always does," Bernadette Schild had said of a woman who has replaced the absent Lindsey Vonn as the smiling face of U.S. women's skiing. "She makes no mistakes, that's what makes her so fast." Italy's Paoletta Magoni was the previous youngest Olympic slalom champion, winning gold in Sarajevo in 1984 at the age of 19 years and 156 days. Switzerland's Michela Figini won the downhill that same year at the age of 17. The gold was the second in Alpine skiing at the Sochi Games for the U.S. team after Ted Ligety's giant slalom win on Wednesday. (Additional reporting by Martyn Herman, Mark Trevelyan and Annika Breidthardt, editing by Ed Osmond)