Baku: Sebastian Vettel was accused of deliberately driving into his title rival Lewis Hamilton as this year's Formula One championship burst into life during a dramatic Azerbaijan Grand Prix.

Red Bull's Daniel Ricciardo won what will be regarded as a race for the ages, following three safety car periods, one red flag and a series of notable incidents.

"I didn't think I'd win for all my money, but this was the race we expected last year, all the safety cars and chaos. We had to stay out of trouble and certainly pulled it off today," said Ricciardo. "I can't really believe it. It was a crazy race. We knew the podium was a chance after the restart, then we heard of the problems with Lewis and Seb."

It was Hamilton's clash with Vettel which will be the main talking point after the Ferrari driver was hit with a penalty for colliding twice with the Briton.

Yet despite his 10-second stop-and-go penalty - after the stewards in Baku deemed Vettel's actions to be dangerous - the German still managed to extend his title lead to 14 points after Hamilton was forced into an unscheduled pit stop when his headrest came loose. Vettel crossed the line in fourth place with Hamilton in fifth.

The pivotal moment of the race in what could prove to be the pivotal moment of this year's championship battle occurred on lap 20.

With the Safety Car out for a third time, as debris littered the 3.7-mile track following a number of collisions through the pack, Vettel rammed into the back of Hamilton.

Then, the 29-year-old German, furiously gesticulating with both hands, pulled alongside his rival, before inexplicably ramming into the side of Hamilton's Mercedes. Hamilton's rivalry with Vettel had, until that point, been built on cordial relations. It evaporated in an instance. "He brake tested me," yelled Vettel over the team radio. "What the f*** is going on?"

Hamilton then gave his version of events to the Mercedes pit wall. "Vettel literally came alongside and hit me," the Briton said.

The race was then red-flagged with more debris on the track after the Force India drivers of Esteban Ocon and Sergio Perez were involved in a collision and Kimi Raikkonen suffered a rear puncture.

As Hamilton returned to the pit lane on lap 22, with the race suspended, he left his cockpit before examining the back of his car. A Mercedes mechanic, armed with a screwdriver and pliers patched up the bodywork on the rear of his car, and Hamilton was good to go for the re-start.

Hamilton suggested that his world title rival had got off lightly. "I didn't brake-test him. I controlled the pace," he said. "Like all the other restarts I slowed down in the same spot. He was obviously sleeping and jumped into the back of me. He got away scot free. He still finished fourth - I think it's a disgrace.

"If he wants to prove he's a man I think we should do it out of the car face-to-face. Imagine all the young kids watching F1 today and seeing that behaviour from the four-time world champion." (Agencies)