Omar Fraile showed incredible stamina to win stage 11 of the Giro d'Italia, while Tom Dumoulin maintained his advantage in the general classification.
Fraile displayed the prowess that has seen him top the mountains classification at the past two editions of the Vuelta a Espana, moving joint-top of the King of the Mountains standings after mastering the 161-kilometre stage for his first section win at a grand tour.
Dumoulin held his own up against specialist climbers and GC rivals Nairo Quintana and Vincenzo Nibali on the gruelling route from Ponte a Ema to Bagno di Romagna to ensure his lead of two minutes and 23 seconds remained intact.
Dimension Data rider Fraile was joined in making a break ahead of the Passo della Calla - the second of the day's four climbs - by Mikel Landa and took the points at the summit.
Fraile and Landa were reeled in ahead of an arduous but thrilling ascent of Monte Fumaiolo, with Pierre Rolland's attack closed down by the resurgent Spaniard.
Rui Costa navigated the descent expertly to give himself a chance at the finish, but, with the chasing pack closing in over the final kilometres, Fraile's last burst put him across the line first.
While Dumoulin dug deep, Geraint Thomas and Steven Kruijswijk were dropped from the maglia rosa group on the final climb to severely hit their respective GC challenges.
GOOD DAY/BAD DAY
Before the stage got underway, Trek-Segafredo announced that two-time and reigning points classification winner Giacomo Nizzolo's campaign was at an end.
The 28-year-old sat 14th in the points rankings on 43 - 148 behind leader Fernando Gaviria - prior to stage 11 and was unable to continue the defence of his title due to persistent allergies.
Nizzolo said in a statement: "Of course I'm unhappy to have to leave the Giro. I can tell you it was definitely the hardest race I've ever done because of my illness; I was struggling every day.
"I tried my best to take the Italian champion's jersey around Italy. Every day I was there, suffering, to honour the jersey and the Giro."
1. Omar Fraile (Dimension Data) 4:23:14
2. Rui Costa (UAE Emirates)
3. Pierre Rolland (Cannondale-Drapac)
4. Tanel Kangert (Astana)
5. Giovanni Visconti (Bahrain-Merida)
1. Tom Dumoulin (Team Sunweb) 47:22.07
2. Nairo Quintana (Movistar) +2:23
3. Bauke Mollema (Trek-Segafredo) +2:38
4. Thibaut Pinot (FDJ) +2:40
5. Vincenzo Nibali (Bahrain-Merida) +2:47
1. Fernando Gaviria (Quick-Step Floors) 191
2. Jasper Stuyven (Trek Segafredo) 160
3. Andre Greipel (Lotto Soudal) 129
KING OF THE MOUNTAINS
1. Jan Polanc (UAE Team Emirates) 44
2. Omar Fraile (Dimension Data) 44
3. Nairo Quintana (Movistar) 35
Having battled their way through a gruelling queen stage, things will be far more routine on Thursday.
A largely flat ride will begin in Forli and include two uncomplicated climbs before passing through urbanised areas like Modena, where roundabouts and pedestrian islands will be the main obstacles, en route to the finish.