Although his Russian Grand Prix only lasted four laps before he retired with a brake issue on his Toro Rosso, Pierre Gasly said he experienced a "really scary" moment when his visor was struck by a piece of debris on the opening lap.

Gasly was following Daniel Ricciardo, who sustained front wing damage at Turn 2, and found himself in a terrifying situation.

"I think Daniel lost a piece of carbon that went straight into my visor," he said. "This was really, really scary because I thought it was going through and straight in my eye, but it hit my visor and fell in the cockpit, so in Turn 4 I had to take the carbon piece and throw it from the cockpit."

The debris entered Gasly's cockpit under the Halo head protection device and the Frenchman thought he was going to be seriously injured.

"I had about 0.5s to see it flying and hitting the visor," he said. "It was like a winglet that maybe came from somewhere from contact with Daniel, but it came like pointing towards me and straight at my right eye.

"When I saw it coming I thought 'F--- it's going through the visor' but the visor is really strong because it just hit it and fell into the cockpit."

If that wasn't bad enough, Gasly then spun at Turn 4 when his front brakes failed just as the same problem struck teammate Brendon Hartley at Turn 2.

"I don't want to go too much into details because they are still analysing to understand exactly what happened, if it's related to temperatures or calipers or brake-by-wire," he explained. "But we just lost the front brakes completely.

"They lost the sensor as well after Turn 3 and straight away for me the pedal was really long and really poor efficiency. It's a strange thing that both cars had the same thing at exactly the same time of the race. It's a bit strange."