Vincenzo Nibali all but wrapped up overall victory of the Giro d'Italia with a magnificent solo win in heavy snow on stage 20.
The 28-year-old Italian attacked his rivals 2.5km out from the spectacular summit finish at Tre Cime di Lavaredo and crossed the line 17 seconds in front of second-placed Fabio Duarte and 19 seconds ahead of third-placed Rigoberto Uran.
It extended his lead in the general classification to 4min 43sec and only a catastrophe on Sunday's flat stage into Brescia can now deny him a maiden Giro triumph.
The victory also saw Nibali take over from Mark Cavendish at the top of the points classification. He leads by 11 points, but the Briton should be able to overhaul that deficit on stage 21, which is almost certain to end in a sprint and offers 25 points to the winner.
Uran, meanwhile, moves up to second overall after Cadel Evans was dropped on the final climb and lost over a minute.
His Colombian compatriot Carlos Betancur was the other big beneficiary of a memorable stage, with his fourth-place finish moving him back into the best young rider's white jersey and elevating him to fifth in the general classification.
After stage 19 had been cancelled due to poor weather, stage 20 delivered a dramatic finale to the Giro's time in the mountains, with stunning scenery and wintry conditions providing a thrilling backdrop to a sublime show of strength from Nibali (Astana), the race's outstanding rider.
The day had been heavily amended due to snow on high ground, with three climbs being taken out and the route subsequently extended to 210km, but none of the drama of the closing kilometres was lost.
Three riders led heading on to the final climb - Eros Capecchi (Movistar), Pieter Weening (Orica-GreenEDGE) and Gianluca Brambilla (Omega Pharma - Quick-Step) - and briefly held a minute's advantage over a thinned-down peloton, but when the pace on the front was stepped up, it soon began to plummet.
By now the snow was also falling and after the lead trio had been swallowed up, Nibali rode himself into Giro legend.
He whittled down the peloton even further with a short attack 3km out that only a handful of riders could respond to, and then obliterated the field completely with another, decisive burst 2.5km from home
Although unable to keep pace, Uran (Team Sky) and Betancur (Ag2r-La Mondiale) set off in pursuit and dropped all the other chasers bar Duarte (Team Colombia), and the three Colombians consequently went on to take places two to four on the stage.
A broken Evans (BMC) followed over a minute later and will now have to settle for third overall.
Watch highlights of stage 20 on Sky Sports 4HD from 9pm
Stage 20 result
1 Vincenzo Nibali (Ita) Astana, 5:27:41
2 Fabio Duarte (Col) Colombia, +17secs
3 Rigoberto Uran (Col) Team Sky, +19
4 Carlos Betancur (Col) Ag2r-La Mondiale, +21
5 Fabio Aru (Ita) Astana, +44
6 Franco Pellizotti (Ita) Androni-Giocattoli, +48
7 Domenico Pozzovivo (Ita) Ag2r-La Mondiale, +54
8 Damiano Caruso (Ita) Cannondale, +58
9 Darwin Atapuma (Col) Colombia, +1.00
10 Rafal Majka (Pol) Saxo-Tinkoff, +1.04
14 Cadel Evans (Aus) BMC, +1.30
1 Vincenzo Nibali (Ita) Astana, 79:23:19
2 Rigoberto Uran (Col) Team Sky, +4.43
3 Cadel Evans (Aus) BMC, +5.52
4 Michele Scarponi (Ita) Lampre-Merida, +6.48
5 Carlos Betancur (Col) Ag2r-La Mondiale, +7.28
6 Przemyslaw Niemiec (Pol) Lampre-Merida, +7.43
7 Rafal Majka (Pol) Saxo-Tinkoff, 8.09
8 Benat Intxausti (Spa) Movistar, 10.26
9 Mauro Santambrogio (Ita) Vini Fantini, +10.32
10 Domenico Pozzovivo (Ita) Ag2r-La Mondiale, 10.59
1 Vincenzo Nibali (Ita) Astana, 128 points
2 Mark Cavendish (GB) Omega Pharma - Quick-Step, 117
3 Cadel Evans (Aus) BMC, 111
4 Carlos Betancur (Col) Ag2r-La Mondiale, 108
5 Rigoberto Uran (Col) Team Sky, 102
Blue (mountains classification) - Stefano Pirazzi (Bardiani Valvole - CSF Inox)
White (best young rider) - Carlos Betancur (Ag2r-La Mondiale)