The formative rounds of the new Formula One campaign have been played out against the backdrop of Hamilton versus Sebastian Vettel in what could yet prove to be a rivalry for the ages.
But the title protagonists may now have to make room for three after Bottas, the understated Finnish driver who has replaced Nico Rosberg at Mercedes this season, turned in the finest moment of his career under the floodlights in Bahrain.
It was Hamilton who appeared destined to claim his seventh consecutive pole in a row - just one short of Ayrton Senna's record - only for Bottas to edge out Britain's triple world champion with his final roll of the dice in a thrill-a-minute qualifying session.
While both Hamilton and Vettel failed to improve on their final timed laps, Bottas delivered when it mattered most to beat Hamilton to pole by just two hundredths of a second on this 3.4-mile circuit.
Hamilton celebrated Bottas's pole lap almost like one of his own. Moments after stepping out of his car, he grabbed his team-mate from behind and offered his hand in celebration. His ensuing smiles appeared genuine. It was certainly not a reaction he would have reserved for the man who use to occupy Bottas's Mercedes cockpit.
"It is early days to speak about the title fight, and it is going to be as is a massively long season, but I feel like I am in the game," Bottas, 27, said.
"For a short period of time you have to enjoy what you have done over the weekend, but the main point is tomorrow so there is no point starting to dream about anything."
Hamilton, sitting next to his team-mate was beaming with pride.
F1 DRIVERS TABLE | 2017
|3||Max Verstappen||Red Bull||25|
|6||Daniel Ricciardo||Red Bull||12|
|7||Carlos Dainz Jnr||Toro Rosso||10|
|8||Felipe Massa||Toro Rosso||8|
|9||Sergio Perez||Force India||8|
|10||Kevin Magnussen||Haas F1||4|
|11||Daniil Kyvat||Toro Rosso||2|
|12||Esteban Ocon||Force India||2|
|14||Romain Grosjean||Haas F1||0|
"Firstly, a big congratulations to Valtteri," the Briton said. "He has been working so hard and jelled so well with the team. Today he was just quicker, and did a better job, so hats off to him.
"He is getting stronger and stronger. It always was, at least a three-way battle as Valtteri has been right there with us from the beginning, so nothing changes."
For all of Hamilton's brilliance, he has never been comfortable with losing, but that appears to have changed this term - firstly after Vettel triumphed in Australia and now here on Saturday night. He is relishing the fight, and in Bottas, perhaps a new rival?
"It is great how close it is between the teams because it brings out the best in each driver," Hamilton, five years Bottas's senior, said.
"When you feel like you are at your best, and you do a good job and you are fighting against someone else who is doing just as good a job, it is that much more exciting, and the more drivers we have in the mix the more intense it gets.
"There are going to be lots of ups and downs but Valtteri is definitely keeping me on my toes and I am thoroughly happy for him today.
"I know how special it is to get your first pole - you dream of it as a kid - and tomorrow could be his first grand prix victory, but I will try my hardest to win."
Vettel, who lines up in third, was four tenths of a second slower than Bottas, but his Ferrari should be closer to the Mercedes in race trim. Daniel Ricciardo qualified fourth for Red Bull.
Jolyon Palmer, Britain's number two, has endured a torrid start to the new season, but he progressed to Q3 - the final phase of qualifying - for the first time in his career, and starts a lofty 10th.