* Zagitova leads after new world record
* Medvedeva second, Canada's Osmond third (Adds quotes, details)
By Soyoung Kim and Elaine Lies
GANGNEUNG, South Korea, Feb 21 (Reuters) - Alina Zagitova took the lead in women's Olympic singles figure skating with a world record short skate on Wednesday, giving her a strong chance of becoming the first Olympic Athlete from Russia to win gold in Pyeongchang.
Zagitova's routine to "Black Swan" featured three triple jumps, including a triple Lutz and triple loop combination, and was awarded 82.92 points.
"I'm happy to have a clean skate and really grateful to myself for that," the 15-year-old said via a translator.
"I don't think it was my best, I can be better. My next goal is to of course have a clean free skate."
Should she win gold in the final on Friday, Zagitova will be the second youngest to do so. America's Tara Lipinski was also 15 when she topped the podium in Nagano in 1998, but was about a month younger than Zagitova.
Her compatriot Evgenia Medvedeva, who set a world record before Zagitova broke it about 15 minutes later, was second on 81.61 points. Canada's Kaetlyn Osmond was third on 78.87.
"It was not my best but it was okay," Medvedeva told reporters. "Every day I see Alina working so hard and she did her best today," added the 18-year-old who trains with the same coach as her compatriot.
Medvedeva was for a long time favoured to top the podium in Pyeongchang but suffered a broken foot which reduced her training time and she lost for the first time in two and half years in January when she was beaten by Zagitova at the European Championships.
"I was calm performing the routine, the game will go on. I am happy with setting a new personal record," Medvedeva said.
"I'm good friends with Alina, I practise together with her and talk with her all the time."
Olympic Athletes from Russia have yet to win a gold medal at the Games, but both skaters shrugged off the prospect of changing that.
"I'm trying not to think about medals," Medvedeva told a news conference. "My goal is to have a clean free skate and be satisfied with myself inside.
"It's not that I want to get out on the ice to prove anything, I just want to skate cleanly," Zagitova said.
Both women said they are the best of friends - until they strap on their skates.
"Evgenia and I are very good off the ice, but during the time on the ice and during competitions, I personally get this feeling of rivalry," Zagitova said. "It's not bitter or personal, but it's there."
Japanese skaters Satoko Miyahara and Kaori Sakamoto were in fourth and fifth places.
"I strongly wanted to do well today," said Miyahara, who made a comeback late last year from a hip injury that kept her out of competition and off the ice for most of 2017.
"We're not done yet. I hope to continue to do well in the free skate."
Mirai Nagasu of the United States came into the event with high expectations but fell on her triple Axel after becoming the first American to nail it in the Olympics during the team competition and she bobbled her triple loop to end up ninth.
"Today wasn't my day, but my triple triple was still pretty good so I'm happy about that," Nagasu said.
Writing by Elaine Lies,; editing by Ed Osmond