Australian national champion Rohan Dennis won the opening time trial of La Vuelta ahead of Team Sky's Michal Kwiatkowski in Malaga.
BMC's Dennis completed the eight kilometre circuit in a time of nine minutes 39 seconds, six seconds ahead of Kwiatkowski who was the best placed of the general classification hopefuls in the final Grand Tour of the season.
Nicolas Roche was 43rd, 35 seconds behind team-mate Dennis, while Dan Martin was three seconds after Roche in 57th. A total of 176 riders raced.
Dennis, who also won the opening stage of last year's Vuelta, said: "Kwiatkowski put on a lot of pressure. Honestly I was hoping the time would be a little bit slower so there was less stress coming into it.
"In the end you can only do what you can do and just put everything out there and hope for the win."
Kwiatkowski served as a key rider in Geraint Thomas' Tour de France victory in July but is getting his own chance to lead Sky in a Grand Tour in Spain with neither defending champion Chris Froome nor Thomas taking part.
"It was a good ride from me but at the end of the day not good enough," Kwiatkowski told Eurosport.
"Congratuations to Rohan Dennis, it was such an impressive ride, he was unbeatable today."
Kwaitkowski's time was enough to give him a cushion of 23 seconds over Mitchelton-Scott's Simon Yates, 24 seconds over Movistar's Nairo Quintana, and 45 seconds over Dennis' team-mate Richie Porte.
Bahrain-Merida's Vincenzo Nibali, racing here after his Tour bid was ended by a crash caused by a fan on Alpe d'Huez, struggled to keep pace.
He finished 40 seconds off Dennis' time, suggesting team leadership may belong instead to Jon Izagirre who was 16 seconds off Kwiatkowski.
Sky may not have many of their big hitters in the race, but they still finished with three riders in the top 10, while 23-year-old Londoner Tao Geoghegan Hart was 17th, 24 seconds down, as he makes his Grand Tour debut.