Hamilton and Bottas came within centimetres of a collision as they drove wheel-to-wheel through the opening three bends in Baku but, thanks to the skill of both men, damage was avoided.
Bottas prevailed and it was where the race, which failed to live up to expectations, was ultimately won. The Mercedes drivers were allowed to fight to the chequered flag but Hamilton did not have enough in the tank to stop Bottas from winning for a second time this season. The Finn now leads the five-time world champion by one point in the standings.
Mercedes became the first team to start the season with four one-two finishes.
On a poor weekend for Ferrari, Sebastian Vettel never troubled the silver cars. The German finished a distant third, falling 35 points behind Bottas in the process.
Charles Leclerc crossed the line in fifth – his race compromised following a costly crash in qualifying. The Ferrari junior started eighth and, out of sync with the front-runners on a different strategy, led for 20 laps. But his challenge faded when he stopped for tyres. He can take some comfort from claiming the fastest lap, and with it, a bonus point, but he is 40 points off the championship summit.
Hamilton is bidding for a sixth world crown this season, and despite a resurgence of sorts by Bottas – indeed, the Finn failed to win once last year in the sport’s fastest car – it seems improbable that the British driver will be beaten by his team-mate over the course of 21 rounds.
“Selfishly, I could have pushed a lot harder,” said Hamilton. “Ultimately I lost out in that but that is the sacrifice you sometimes have to make in order for the team to win. If there was a Ferrari there it would have been a lot different, but that is how it will continue for the rest of the year.
“Valtteri and I have a lot of respect for each other. You can see that. We discuss the start before the race, we agree as gentlemen, and we stick to it. Valtteri was very fair in giving space, and after that he was faultless. He truly deserved the win.”
On a largely uneventful afternoon, Daniel Ricciardo provided some amusement when he ran off the circuit with Daniil Kvyat, and then accidentally reversed into the Russian’s Toro Rosso, ending both of their races.
McLaren, meanwhile, continued their semi-revival with a first double-points finish of the year, Carlos Sainz taking seventh to finish one spot ahead of British teenager Lando Norris.