Ricciardo blasts Stroll after Chinese Grand Prix collision

Daniel Ricciardo accused Lance Stroll of not looking where he was going after the Aston Martin driver said an "odd concertina effect" was to blame for him slamming into the Australian's car at Sunday's Chinese Grand Prix.

Ricciardo retired with substantial damage from the incident during a safety car restart as cars suddenly bunched up into the hairpin.

Stroll was given a 10-second penalty by Formula One stewards for causing a collision, a punishment he felt was undeserved.

"It's so frustrating. Obviously, racing incidents happen but behind a safety car, that should never happen," Ricciardo told reporters.

"What makes my blood boil is I've watched his onboard (video) to see it from his perspective, to try to maybe have some type of understanding.

"As we start braking, you can see his helmet turn right. He’s looking at the apex of turn 14, he’s not even watching me."

Stroll finished 15th and said he had been in the wrong place at the wrong time.

"Someone braked at the front of the pack, I don’t know who, and then everyone stopped. The car in front of me stopped from like 60km/h to zero, and then boom, so it was really stupid. It’s one of those," he told reporters.

"I got a penalty because of the end result that I hit Ricciardo but it's not like everything was normal and I just ploughed into the back of him.

"It was a really odd concertina effect that I would have liked to see the stewards take into consideration maybe a bit more."

Ricciardo, who has yet to score in five races and has retired in his last two, had hoped to seize some momentum in China after out-qualifying teammate Yuki Tsunoda.

The Australian, who started the season as a candidate to return to the main Red Bull team alongside triple champion Max Verstappen, is under some pressure after Tsunoda scored in Australia and Japan.

To add to Ricciardo's unhappiness, stewards gave him two penalty points and a three-place grid drop for the next race in Miami after he overtook Nico Hulkenberg's Haas under safety car conditions.