Dylan Groenewegen caused a crash which left rival Fabio Jakobsen in a medically induced coma.
Cyclist George Bennett was part of a breakaway that gained time on the tour frontrunners.
Stage 19 was cut in half, after riders expressed concerns over the 258km length.
The Kiwi rode well, crossing the line in ninth place on the opening day of the Vuelta a Espana.
Julian Alaphilippe was left sprawled on the road with broken bones in his hand.
The UCI plans to investigate the crash, which saw a barrier blow in front of two riders.
Frenchman Arnaud Demarre's victory was overshadowed by the horror crash.
Primoz Roglic edged Julian Alaphilippe to win the Liège-Bastogne-Liège race.
The men's road race was won by Frenchman Julian Alaphilippe.