DOBBIACO, Italy (AP) -- Alexey Poltoranin of Kazakhstan took advantage of different equipment to win the fourth stage of the Tour de Ski on Wednesday, while overall leader Petter Northug Jr. had his overall lead reduced to just 1.5 seconds.
Poltoranin, the only top-ranked competitor to use skate skis, finished half a second ahead of Evgeniy Belov of Russia in the 10-kilometer individual start classic leg.
Martin Sundby of Norway, the defending champion, placed third, 4.2 seconds back.
Sundby closed the overall lead on his Norwegian teammate Northug Jr., who crossed seventh, 22.8 behind, marking the first time he has not finished on the podium in this year's Tour.
A women's 5-kilometer classical race was scheduled for later.
The seven-stage Tour concludes on Sunday with the traditional climb up Mount Cermis.