DOBBIACO, Italy (AP) Sergey Ustiugov is two wins away from the first clean sweep of all seven stages in the 11-year history of the Tour de Ski cross-country race.
For his fifth straight win Friday, the Russian finished 0.4 seconds ahead of Maurice Manificat of France and 16.6 ahead of Simen Hegstad Krueger of Norway in a 10-kilometer individual freestyle event.
Ustiugov had already set the tour record with his fourth straight win two days earlier in Oberstdorf, Germany.
''I had extra motivation today because it's my mother's birthday,'' Ustiugov said. ''I pushed very hard from the start. I wanted to extend the overall Tour de Ski lead.''
American skier Jessica Diggins won the 5K women's fifth stage, excelling on the downhill sections.
Ustiugov held a 2.4-second advantage at the last checkpoint and narrowly held on. Upon crossing the finish line, he collapsed stomach-down on the snow in exhaustion, his lungs pumping so hard that his body bounced up and down.
Ustiugov extended his Tour lead to 1 minute, 34.1 seconds ahead of Martin Johnsrud Sundby of Norway, who still holds a 246-point advantage over Ustiugov in the World Cup standings.
Sundby, who won the Tour two of the past three years, had a difficult day, finishing 14th in the stage, 36.9 seconds behind Ustiugov.
Three-time winner Dario Cologna of Switzerland is third in the Tour, 2:07.5 behind.
It was the 10th World Cup win for the 24-year-old Ustiugov.
Diggins finished 13.6 seconds ahead of Krista Parmakoski of Finland and 14.6 ahead of American teammate Sadie Bjornsen.
It was the second World Cup win this season for Diggins and third in her career.
''This is just my thing, I guess. I love this course. I love the downhills,'' Diggins said. ''And it's great to see (Bjornsen) up here with me. I have so much belief in her.''
Heidi Weng of Norway finished fifth in the stage and took the tour lead from Stina Nilsson of Sweden, who struggled in 20th on Friday.
Weng, who finished third in the tour the past three years, leads Norwegian teammate Ingvild Flugstad Oestberg by 11.1 seconds. Nilsson dropped to third, 16.3 behind.
The Tour de Ski concludes Sunday with the climb up Mount Cermis in Val di Fiemme.