Simon Yates protected his fragile one-second lead at the Vuelta a Espana as Alessandro De Marchi won Tuesday's 11th stage.
Mitchelton-Scott's Yates never escaped from the peloton on a day in which he saw his advantage repeatedly threatened, yet he came through remarkably unscathed after a hectic finish.
Groupama–FDJ rider Thibaut Pinot set the wheels in motion for an entertaining final 100km when he - 16th in the general classification and less than three minutes off the pace - made his move.
Yates' team-mates initially set off in pursuit of the Frenchman before settling on having Jack Haig join the breakaway group, although the gap was stretched to see Pinot ride for much of the remainder of the day with a projected lead.
Counter-attacks harmed Pinot's standing but he maintained a strong position until, in the pouring rain, De Marchi and Jhonatan Restrepo broke clear as, further back, the peloton splintered.
BMC's De Marchi had too much for Restrepo as he won by 28 seconds, but the drama was not finished there, even with Pinot fading.
Nairo Quintana, of Movistar, made a move to snatch the race lead from Yates, attempting to streak away from the group of favourites but coming up short.
Yates was instead happily stationed alongside Quintana as he crossed the line 10 seconds behind Pinot, with no damage done despite the chaos.
Alejandro Valverde may not have done enough to claim the red jersey, but he will ride in green on Thursday after Peter Sagan endured a difficult day.
The Bora-Hansgrohe man, who led the way in the points classification, fell off the back of the peloton long before the end of the race and failed to collect a single point.
Valverde nudged to the top of the standings by two points, while he remains just a second behind Yates in the general classification.
Bauke Mollema closed the gap slightly to Luis Angel Mate for the King of the Mountains, but he remains 30 points short in third place.
1. Alessandro De Marchi (BMC Racing Team) 4:52.38
2. Jhonatan Restrepo (Katusha-Alpecin) +0.28s
3. Franco Pellizotti (Bahrain-Merida) +0.59s
4. Nans Peters (Ag2r La Mondiale) +1.24s
5. Dylan Teuns (BMC Racing Team) +1.45s
1. Simon Yates (Mitchelton-Scott) 45:57.40
2. Alejandro Valverde (Movistar) +0.01s
3. Nairo Quintana (Movistar) +0.14s
1. Alejandro Valverde (Movistar) 85 points
2. Peter Sagan (Bora-Hansgrohe) 83 points
3. Elia Viviani (Quick-Step Floors) 66 points
King of the Mountains
1. Luis Angel Mate (Cofidis) 60 points
2. Benjamin King (Dimension Data) 33 points
3. Bauke Mollema (Trek-Segafredo) 30 points
There is no let up as Thursday's 12th stage takes in a hilly 181km ride from Mondonedo to Faro de Estaca de Bares, with narrow roads and a series of small climbs late on.