Irish rider Sam Bennett grabbed his chance after dodging a mass pile-up with barely a kilometre to go on Friday to win the fourth stage of the Tour of Burgos.
With the pack jostling for position ahead of the anticipated sprint finish up a short slope, Italian Jacopo Guarnieri, the leadout man for French sprinter Arnaud Demare, fell on the final corner, causing chaos.
While his rivals fell, braked or took evasive action, Bennett charged up the hill. The Deceuninck-Quickstep rider finished four seconds clear of his pursuers at the end of the flat 163-kilometre stage from Gumiel de Izan to Roa de Duero.
Demare outsprinted Italian Giacomo Nizzolo for second.
"I was slowed down a lot," said Demare. "I was very close to giving up and then I started again, but Sam Bennett was long gone."
With all the pack credited with the same time, young Belgian Remco Evenepoel retained his 18-second lead over New Zealander George Bennett.
On Saturday, the fifth and final stage covers 158km and ends with a sharp climb into Lagunas de Neila.