VAL DI FIEMME, Italy (AP) Defending champion Therese Johaug won her first stage in this year's Tour de Ski on Saturday, while Tim Tscharnke beat Alexey Poltoranin in a photo finish in the men's event.
Johaug clocked 33 minutes, 10.4 seconds in the 10-kilometer classical mass start race, edging out Tour leader Marit Bjoergen by 1.1 seconds. Heidi Weng was 5.5 seconds behind in an all-Norwegian podium.
''I worked yesterday with my coach on my classical technique,'' Johaug said. ''I knew Marit would be strong on the last hill but I could follow her. My skis were amazing. I don't think I have ever had so good skis like today.''
Bjoergen, who had won the previous five stages, leads Weng by 2:11.2 and is 2:50.3 ahead of Johaug in the overall standings. The six-time Olympic champion remains on course for a first Tour win when the competition concludes Sunday with the traditional climb up Mount Cermis.
''Second place today is great,'' Bjoergen said. ''It was only three of us fighting for bonus seconds ... I knew I had to speed on the last climb but Therese caught me on the downhill.''
Elizabeth Stephen of the United States moved up to sixth overall after finishing fifth, in her best result of the Tour.
Tscharnke recorded his first World Cup victory in more than a year as the German edged out Poltoranin of Kazakhstan to win the 15K classic in 46:48.8. Dario Cologna recovered from a fall to finish 0.4 seconds behind.
''It's a little bit surprise for me to win today,'' Tscharnke said. ''Thomas (Bing) and me wanted to be in the front of the pack. We helped each other. We did not focus on sprints, we just wanted to go for a good position in the finish.''
In the closest competition of the season, fourth and fifth places were also decided by a photo finish, with Stanislav Volzhentsev narrowly beating Alexander Bessmertnykh. The Russian duo were 0.7 seconds slower than Tscharnke.
Petter Northug finished 21st and saw his overall lead cut to 3.1 by fellow Norwegian Martin Johnsrud Sundby, who moved into second. Calle Halfvarsson of Sweden slipped into third, 26.8 behind Northug.
''Today the plan was to fight for bonus seconds,'' Northug said. ''I knew many skiers were saving energy for the finish. It will be a hard fight for the podium tomorrow. It has been a tough Tour de Ski. If you have a really bad day you can easily lose many minutes.''