Chinese Grand Prix winner Daniel Ricciardo picked up where he left off in Shanghai, going fastest in the second free practice session on Friday in Baku, where world champion Lewis Hamilton struggled to keep up.
Ricciardo enjoyed the sixth race victory of his Formula One career last time out and showed he means business again in Azerbaijan this weekend, the Australian clocking a time of 1 minute 42.795 seconds to set the pace ahead of qualifying on Saturday.
Hamilton, who is yet to win in the first three races of his title defence, was a relatively distant fifth fastest, behind Mercedes team-mate Valtteri Bottas, as well as Ferrari's Kimi Raikkonen and Ricciardo's Red Bull team-mate Max Verstappen, who were second and third fastest respectively.
Verstappen collided with a wall in the first session and was one of several drivers to lock up in the second, before limping back to the pit lane amid concerns from his garage of engine trouble.
Ferrari's Sebastian Vettel - who infamously intentionally collided with Hamilton in Baku last year - endured a day to forget, the German four-time world champion sitting 11th on the time charts for FP2.
Speaking between the sessions, Red Bull's chief engineer Paul Monaghan was asked in a news conference to assess his team's chances of challenging Mercedes and Ferrari across the season following their strong start to 2018.
He said: "We will develop at the best pace we can, we'll try to operate the car in the most competitive way we can and, actually, we're judged by our opposition, aren't we?
"We'll do what's in our control, get to the end of the year, be as quick as we can and if we're in the hunt, we're in the hunt."