Toto Wolff believes that Mercedes was able to gain relative performance over Ferrari in the cooler Baku temperatures, which took it to its third qualifying one-two of the year.
As the sun sank lower behind the city buildings, the track surface cooled, which Wolff thinks brought Mercedes back into the game against Ferrari.
"They [Ferrari] were very quick yesterday and they were extremely quick in FP3 this morning," Wolff said. "That was something which we didn't know how to solve, because the gap was big.
"When you see this kind of gap, it's not that the car has lost performance, it's just the car is not in the right tyre operating window.
"The more the [qualifying] session went on, the more we got it there. Towards the end, from a car that was not making the drivers happy in the morning, we ended up with a car in Q3 that was good.
"We gained relative performance with the dropping temperatures. This morning, Ferrari were a league of their own, and once it got cooler, the competitive order changed."
Mercedes also stopped at the end of the pit lane to allow cars to pass before it set its final laps in Q3, ensuring that Bottas and Hamilton would be the last to cross the line.
Wolff explained that the team attempted to do something different after seeing a pattern emerge in recent races, in which other teams would wait for Mercedes to take to the track.
"You always need to evaluate between trying to get a tow effect and compromising your out lap. You can see how wrong it can go, in Shanghai some of the cars weren't able to cross the line.
"So in each of the qualifying sessions, we saw a pack and then everyone waited for us to go out. This time we thought 'we're going to try something else'.