Josef Cerny won stage 19 of the Giro d'Italia after Friday's leg was shortened by more than 50 per cent following a protest from the peloton.
The riders were set to contest the longest stage of the race following back-to-back mountain sections but after health concerns were raised they were transported from Morbegno to Abbiategrasso on buses, reducing the distance from 258 kilometres to 124km.
Asti was expected to host a sprint finish at the end of a flat stage but maglia ciclamino contender Peter Sagan called off the chase of a 14-man breakaway after no one appeared willing to share the workload at the front of the peloton with his Bora-Hansgrohe team-mates.
Victor Campenaerts forced a split at the front but Cerny pushed again with around 22km remaining and quickly established a lead of around 40 seconds.
Cerny, who finished fifth in the time trial last Saturday, was able to go solo to secure a first Grand Tour stage win, with Campenaerts unable to close the gap late on.
"The stage was definitely not [what I expected]. We were standing at the start line and the organiser said we can rest a little bit, it's very nice of him because we had the last three days really heavy, and it was a really hard day also today with the rain," said Cerny.
"But I'm really happy. I was lucky in the breakaway and we were working together. And then in the final it was just who had better legs. I'm very happy. I still cannot believe it because it was so quick. It was incredible. I cannot describe it."
Wilco Kelderman retained his grip on the maglia rosa with none of the General Classification contenders able to make in-roads on the short, flat route.
Tao Geoghegan Hart tried to gain some valuable seconds in the final kilometre but was unable to force a split at the front of the peloton and remains 15 seconds adrift in third.
STAGE RESULT
1. Josef Cerny (CCC Team) 02:30:40
2. Victor Campenaerts (NTT Pro Cycling) +00:18
3. Jacopo Mosca (Trek-Segafredo) +00:26
4. Simon Clarke (EF Pro Cycling) +00:26
5. Iljo Keisse (Deceuninck-Quick-Step) +00:26
CLASSIFICATION STANDINGS
General Classification
1. Wilco Kelderman (Team Sunweb) 80:29:19
2. Jai Hindley (Team Sunweb) +00:12
3. Tao Geoghegan Hart (INEOS Grenadiers) +00:15
Points Classification
1. Arnaud Demare (Groupama-FDJ) 221
2. Peter Sagan (Bora-Hansgrohe) 184
3. Joao Almeida (Deceuninck-Quick-Step) 94
King of the Mountains
1. Ruben Guerreiro (EF Pro Cycling) 234
2. Thomas De Gendt (Lotto-Soudal) 122
3. Tao Geoghegan Hart (INEOS Grenadiers) 115
WHAT'S NEXT?
The penultimate stage is a 190km ride across the Alps including 3,500 metres of vertical altitude gain, meaning there could be plenty of drama in the GC.