TOBLACH, Italy (AP) Six-time Olympic champion Marit Bjoergen remained on course for a first Tour de Ski victory as she won her fifth straight stage on Thursday.
Bjoergen, who has twice finished runner-up in the World Cup's annual mini competition, won the 15-kilometer pursuit to extend her lead over Norwegian compatriot Heidi Weng to 2 minutes, 3.8 seconds.
Another Norwegian, defending champion Therese Johaug, was third, finishing nearly three minutes behind. Johaug fell 3:01.4 behind Bjoergen overall.
''No victory is easy but I felt amazingly strong and I could focus only on my performance,'' Bjoergen said. ''I am happy I could increase the gap a little bit. I am looking forward to the next competitions. It looks good for me but there are still two competitions until the end.''
It was Bjoergen's seventh consecutive victory overall, including two World Cups before the Tour.
It was closer in the men's leg, where Petter Northug of Norway beat Calle Halfvarsson by two seconds in the 25K pursuit to extend his lead over the Swedish skier to seven seconds.
Martin Johnsrud Sundby started the day 1.5 seconds behind Northug but the defending champion fell to third, 12.2 behind.
''Martin was very strong,'' Northug said. ''When he increased the speed we could gain many seconds. Also (Evgeniy) Belov did a lot of work.
''I was tired in the third and fourth lap. I tried to save some energy for the last lap. It is a close Tour de Ski and we will see what happens in the mass start in Val di Fiemme.''
Saturday's sixth leg includes men's 15-kilometer and women's 10-kilometer classical mass start races before concluding on Sunday with the traditional climb up Mount Cermis.
''It is going to be the tightest Tour de Ski ever,'' Sundby said.