Exhausted Italian Dario Cataldo almost fell over the finish line to win the queen stage of this year's Vuelta a Espana ahead of Thomas de Gendt, conquering the legendary Cuitu Negru after more than 4500 metres of climbing and a brutal final kilometre that ramped up to more than 20 per cent.
The Cuitu Negru itself, which featured gradients as high as 25 per cent in parts, ripped the Vuelta field to shreds on Stage 16. There was nowhere to hide as the physical and mental battle that the Cuitu Negru posed to riders meant only the best would survive.
Cataldo (Omega Pharma-QuickStep) won after a long day in the break that began when he escaped with de Gendt (Vacansoleil-DCM) on the descent of the Alto de la Cabrunana early in the day.
Katusha had no interest in bringing either rider back into the fold with neither a threat to Joaquim Rodriguez's overall lead, and the two's advantage grew to more than 15 minutes.
The responsibility was left to Saxo Bank-Tinkoff Bank, with Euskaltel-Euskadi an interesting addition to the chase, hoping for a rise in fortune for Igor Anton.
Over the top of the Puerto de San Lorenzo the leading duo still held a healthy lead, and little had changed as the field passed through the town of Santa Marina with 50km still to race.
The penultimate climb of the day, Alto de la Corbetoria, saw Saxo Bank-Tinkoff Bank up the pace. While only a prelude to Cuitu Negru, it was from a simple climb, and Chris Froome (Sky) was the most notable struggler on the sticky gradients near the peak.
Froome did get back into a now heavily depleted field for the assault on Cuitu Negru, but his hopes of a podium finish were becoming increasingly tenuous.
De Gendt and Cataldo were left to ride their own race ahead, while battle royal exploded on the early slopes of Cuitu Negru in the main field behind.
Saxo Bank-Tinkoff Bank lifted the pace and lined things out, hoping to find a weakness in Rodriguez's so far impenetrable armour, but the Spaniard was steadfast as ever.
Jesus Hernandez was the last Saxo Bank-Tinkoff Bank rider to be left at the front for Contador, and by the time he did, Contador only had the Movistar pair of Alejandro Valverde and Nairo Quintana, and Rodriguez for company. Froome was out of the picture, as were Robert Gesink (Rabobank), Andrew Talansky (Garmin-Sharp) and Nicolas Roche (AG2R-La Mondiale).
The hardest part of the climb was still to come however and with that in mind Contador began a repeat of yesterday's machine gun like attacks inside 10 kilometres to the finish.
Each time Rodriguez answered, with Valverde and Quintana yo-yoing, but Contador insisted.
Into the final three kilometres and the average gradient of 13 per cent changed the dynamic of both the attacks and the speed at which they came. Contador was now really fighting with his machine to keep up the tempo, but Rodriguez looked increasingly comfortable.
Ahead, Cataldo and de Gendt were engaging in a slow-motion fight for stage honours, the horrifically steep finale proving the undoing for the Vacansoleil-DCM rider. Cataldo grimaced as he crossed the line, with no celebration, but rather relief from the Italian after an almost abusively hard day in the saddle.
A little over two minutes down the road, Contador had one more attack in him, and made it count. Valverde was distanced immediately, and the anger and power of the move initially looked to have finally cracked Rodriguez. But as has been the way for much of the Vuelta, Rodriguez found a way not only to hang on, but also to launch a counter-move over the top.
The red jersey took third on the stage behind the break, more bonus seconds, and now an overwhelming favourite to secure his first Grand Tour title. The only impediment for the Katusha rider is Saturday's towering stage to Bola del Mundo, but on the way he's riding it seems hard to see Contador, or for that matter anyone else, overcoming him.
Stage 16: 183.5km, Gijon-Cuitu Negru
1 Dario Cataldo (ITA) Omega Pharma-QuickStep 5hr 18min 28sec
2 Thomas De Gendt (BEL) Vacansoleil-DCM 0:00:07
3 Joaquim Rodriguez (ESP) Katusha 0:02:39
4 Alberto Contador (ESP) Saxo Bank-Tinkoff Bank 0:02:41
5 Alejandro Valverde (ESP) Movistar 0:02:58
6 Nairo Quintana (COL) Movistar 0:03:24
7 Igor Anton (ESP) Euskaltel-Euskadi 0:04:07
8 Andrew Talansky (USA) Garmin-Sharp 0:04:15
9 Laurens Ten Dam (NED) Rabobank 0:04:18
10 Robert Gesink (NED) Rabobank 0:04:21
1 Joaquim Rodriguez (ESP) Katusha 63hr 38min 24sec
2 Alberto Contador (ESP) Saxo Bank-Tinkoff Bank 0:00:28
3 Alejandro Valverde (ESP) Movistar 0:02:04
4 Christopher Froome (GBR) Sky 0:04:52
5 Daniel Moreno (ESP) Katusha 0:06:58
6 Robert Gesink (NED) Rabobank 0:07:28
7 Andrew Talansky (USA) Garmin-Sharp 0:08:28
8 Laurens Ten Dam (NED) Rabobank 0:09:00
9 Igor Anton (ESP) Euskaltel-Euskadi 0:09:11
10 Nicolas Roche (IRL) AG2R-La Mondiale 0:11:44