ALPE DI SIUSI, Italy (AP) Dutch rider Steven Kruijswijk had a strong performance in a mountain time trial and opened up a potentially decisive lead in the Giro d'Italia on Sunday.
Pre-race favorite Vincenzo Nibali struggled and had to deal with a dropped chain and spectators blocking his path.
Alexander Foliforov, a Russian with Gazprom-Rusvelo, won the 15th stage, an 11-kilometer (7-mile) entirely uphill leg from Castelrotto to Alpe di Siusi, in 28 minutes, 39 seconds.
''I came to the Giro well prepared for this stage in particular because uphill time trials have always been my forte,'' Foliforov said.
Kruijswijk finished second, 0.16 seconds behind, and Alejandro Valverde was third, 23 seconds back.
''I was close to the victory but most importantly I gained time over my rivals on GC (general classification),'' said Kruijswijk, who also finished second in Saturday's marathon-like stage. ''I did everything for that and I'm confident that I'll be able to defend the Maglia Rosa (pink jersey) during the last week''.
Overall, Kruijswijk leads Esteban Chaves by 2 minutes, 12 seconds, with Nibali third, 2:51 behind.
Kruijswijk, who rides for the Lotto NL-Jumbo team, is attempting to become the first Dutchman to win the Giro. He finished seventh last year.
Valverde is fourth, 3:29 behind.
Chaves finished sixth in the stage while Nibali was 25th, 2:10 behind Foliforov.
Nibali was already losing a lot of time when his chain dropped and he had to change bikes midway through the stage. Then spectators started running alongside Nibali until the Sicilian swiped one of them away with his arm.
Starting with a small incline, the route then got very steep the rest of the way, with an average gradient of 8.3 percent and a maximum of 11 percent.
The finish at an altitude of 1,844 meters (6,050 feet) in Alpe di Siusi showed off Europe's largest high-altitude Alpine meadow, which extends for 52 square kilometers (32 square miles).
After a rest day Monday, Stage 16 Tuesday is a 133-kilometer (83-mile) leg from Bressanone to Andalo featuring three classified climbs, two of them in the second category.
The race ends next Sunday in Turin.