A seemingly straightforward stage 12 across the plains of northern Italy threatened to turn seriously awry for two of the Giro d'Italia's top contenders, Richard Carapaz (Movistar Team) and Domenico Pozzovivo (Bahrain-Merida) when the bunch split late on.
Carapaz and Pozzovivo, fourth and fifth overall, as well as Miguel Angel Lopez (Astana ProTeam), 11th on GC, were in a second group which lost 30 seconds at one point on the twisting, rain-soaked approach to the Imola circuit and the final ascent of the Tre Monti.
Only a full-blown chase by Bahrain-Merida, Astana and Quick-Step Floors - working for Elia Viviani - allowed the chase group to come within sight of a lead peloton of some 50 riders. Some chasers like López made a desperate mid-stage sprint across the gap, others like Pozzovivo and Carapaz were able to make contact a little later when the two groups fused at the foot of the Tre Monti.
Carapaz, fifth overall, had enough energy to make a brief attack later on the climb itself, albeit one which fizzled out fairly quickly. But Movistar continued to go for the stage win with a more sustained charge by Carlos Betancur, who, together with stage 10 winner Matej Mohoric (Bahrain-Merida), was only caught within sight of the line.
A torrential downpour made for a fraught, confused finale, with Simon Yates (Mitchelton-Scott) saying later he had had no idea who was caught behind until the group had returned to the main peloton.
"I'm not actually sure what happened with Carapaz and Pozzovivo, one moment I heard on the radio there was a split in the peloton, but I didn't know how many guys were there," Yates said.
"It was a complicated day because of the rain, with a lot of tension in the last 30 kilometres, when I got dropped," Carapaz said later.
"The descent off that last climb was very dangerous and it made it even more stressful.
"Fortunately Betancur and the rest of the teammates helped me to get back onto the peloton. So we could save the day, everything worked out, and we all but celebrated a win with Betancur. It's just a pity he didn't make it."
Coming soon from Cyclingnews Films: CRESCENDO: Tales from the final week of the Giro d'Italia