The Astana rider attacked at the foot of the highest climb in the 2013 Giro d'Italia to power through the snow and lay claim to the biggest victory of his cycling career.
On a horrible day in the Dolomites, Nibali proved he was the strongest rider in the race when he kicked for home from home at the foot of the Tre Cime di Lavaredo to distance his nearest rivals and cement his grip on the title.
With Nibali's dominance in Thursday's Individual Time Trial and the cancellation of Friday's Stage 19, the rerouted Stage 20 was effectively to be the last chance for the likes of Cadel Evans (BMC) and Rigoberto Uran (Sky) to challenge for overall honours.
But in the end both lost more time, with Evans, Nibali's nearest challenger, suffering badly on a punishing final ascent up the Cima Coppi and slipping to third behind Uran in the general classification.
Nibali now leads Uran by four minutes and 43 seconds, with Evans a further 1:09 adrift.
With just one stage left on this year's Giro, a largely flat route between Riese Pio X and Brescia, Nibali's victory in the Grand Tour is all but confirmed.
Originally, Stage 20 was to be a huge day in the mountains bringing riders over no less than five major climbs, but due to yet more inclement weather race organisers deemed it prudent to amend the route. Having removed the climbs of the Passo Costalunga, Passo San Pelligrino and the Passo Giau, the amended route saw the riders contend with a much flatter passage from Silandro to Tre Cime di Lavaredo, with the two remaining climbs coming in the last 20km.
The early part of the stage was something of a procession as riders kept their powder dry in advance of the Passo Tre Croci and the leg-sapping Tre Cime di Lavaredo which hit 18% gradient at points.
The main break of the day formed after 40km when Stage seven winner Adam Hansen (Lotto Belisol) combined with Pavel Brutt (Katusha), Yaroslav Popovych (Radioshack Leopard) and Giairo Ermeti (Androni Giocattoli) to go clear. They extended their lead to 8:30 at one stage before the massed ranks of Mark Cavendish's Omega Pharma Quick Step took control at the head of affairs. That control was short-lived as Euskaltel took over with Astana in their wheels, clearly thinking of the major climbs later in the day.
The Basque outfit continued to drive the pace for the majority of the stage and at the halfway point the gap began to dip under seven minutes for the first time. From here to the finish the road rose gradually and it was only a matter of time until they were swept up by the fast-moving bunch, although it did take until the bottom of the Passo tree Croci to happen.
With 55 km remaining the riders went through the first of two intermediate sprints of the day. The four breakaway riders took the majority of the points, but back in the bunch and with two points still up for grabs, Mark Cavendish stuck himself out front to mop up two more points and extend his lead in the red jersey category. Cavendish didn't have it all his own way as he was challenged by a Vini Fantini rider on the approach to the line, but he did enough to claim those vital points.
As the snow began to appear on the roadsides, Cannondale took over at the front of bunch and the four leaders saw their lead tumble to three minutes with 30km remaining.
At the second sprint point of the day the leaders had over two minutes and took the points, and Mark Cavendish, who was in determined form, dug deep to ping off the front of the bunch to take the last two points of the day. Cavendish will be happy with four points, but at the end, Nibali overtook his points total to take the red jersey with only one stage remaining.
At the foot of the first climb racing began in earnest. And it wasn't just at the front of the race. Despite being in the break all day, Brutt shook off his three companions and went alone. He continued on in the lead over the top of the Passo Tre Croci, with Pieter Weening (Orica GreenEdge) attacking out of the bunch to follow him over the top just 26 seconds down and mountains classification leader Stefano Pirazzi (Bardiani Valvole-CSF Inox) coming over in third.
Meanwhile, off the back of the group of favourites, Carlos Betancur (AG2R) was having mechanical issues and at one point lost almost a minute, but with a bit of help from his team-mates dragged himself back in to the bunch. While he was out the back, the team of his nearest challenger and rival for the young riders' white jersey Rafal Majka, Saxo-Tinkoff, tried to up the ante. But their efforts were in vain, because Betancur was the stronger climber on the day and wrested the jersey from the shoulders of the Pole.
On the descent of the Passo Te Croci, Weening caught and passed Brutt and was joined by Gianluca Brambilla (Omewga Pharma Quick Step) and Eros Capecchi (Movistar), while they were being chased by Pirazzi and Darwin Atapuma (Columbia), but once the race hit the Tre Cime di Lavaredo these attacks were nullified by a decisive Nibali.
His first attack saw him pull out a slight advantage and he had team-mate Tanel Kangert for company. Immediately Evans was in trouble. Seeing this, Nibali continued with a series of small, calculated attacks which broke the bunch and saw him clear on his own.
Behind Evans was losing time, as the only riders capable of attempting to follow Nibali were Uran and Betancur. As Nibali drove forward through the snow, cheered on by home fans on the road, he rarely looked behind knowing that he had not only the stage in the bag, but also the Cima Coppi, the red jersey and also the overall lead.
Fabio Duarte (Colombia) climbed well to pull himself up to second place on the stage, while Uran took third to move himself into second place overall.
Tomorrow's stage should be largely processional with the only jersey up for contention being the red jersey of points leader. Cavendish will be hopeful of another stage win and claiming back the jersey he has worn for much of this race.
- Sports & Recreation
- Cadel Evans
- Mark Cavendish
- Rigoberto Uran
- Tre Cime di Lavaredo