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.
But it is 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. Hamilton’s Mercedes team-mate Valtteri Bottas recovered from last place after a first-lap collision with Kimi Raikkonen to pip Williams driver Lance Stroll on the line to take second. Stroll, 18, completed the podium.
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.
The race resumed after a 23-minute break with Hamilton once more leading the pack away under Safety Car conditions.
With the earlier incident still fresh in their minds, Hamilton got the drop on Vettel and retained the lead from the German, while Ricciardo made up three positions in one corner as he roared past both Williams drivers and Renault’s
It was a move which would enable the Australian, who started 10th, to win his first race since last October’s Malaysian Grand Prix.
For Hamilton, it looked as though the win was in his pocket, but his headrest – which sits above the cockpit – suddenly started to come loose.
Hamilton frantically tried to repair the flapping piece of silver bodywork by holding it down with one hand on his car with the other hand on his steering wheel as he travelled at speeds in excess of 220mph.
But unsurprisingly the stewards took a dim view of his desperate actions and ordered Mercedes to haul their man in for repair works.
A reluctant Hamilton stopped at the end of lap 31 for 9.3 seconds and was then on his way. He emerged in ninth place. It was at that point Vettel was hit with his penalty which he would serve two laps later.
Vettel, who had claimed no wrongdoing over the team radio for the Hamilton incident, sat in his Ferrari blocks for 10 seconds but emerged ahead of an incandescent Hamilton.
“A 10-second penalty is not enough for driver behaviour like that,” Hamilton said over the team radio.
Both Vettel and Hamilton began their charge back through the pack, but Hamilton was unable to get close enough to get the Ferrari driver although he finished just 0.2 sec behind his title rival following a breathless race. The ramifications, however, are likely to go long into the night.