A heavy crash for Carlos Sainz Jr. ended the final practice session at the Russian Grand Prix on Saturday with the Toro Rosso driver hospitalized.

Sainz lost control of his car on a high-speed stretch heading into a steep right-hand corner, before scraping along the wall and crashing head on into the barriers.

The Spanish driver remained in the car, with part of the barriers covering the cockpit as the medical car quickly attended. Cranes were used to lift the barrier sections off the car before Sainz was placed into an ambulance on a stretcher. He was conscious and moved his arms.

The session was red-flagged immediately after the crash with more than 20 minutes remaining and canceled shortly afterward.

Sainz's teammate Max Verstappen expressed concern over the radio to his team, asking "Is he OK? It looked like a big one." The garage replied that "We lost the power on the car, we don't know."

Mercedes' Nico Rosberg took pole position for the Russian Grand Prix on Saturday ahead of his teammate and title rival Lewis Hamilton.

Rosberg set an unbeatable time of 1 minute, 37.113 seconds midway through the final qualifying session in Sochi to beat Hamilton by more than three tenths of a second.

Hamilton challenged for the top spot with an aggressive final lap but ran off track and aborted the attempt.

Williams' Valtteri Bottas took third ahead of the two Ferraris of Sebastian Vettel and Kimi Raikkonen.