Valtteri Bottas pipped Daniel Ricciardo to set the early pace at the Azerbaijan GP, but Max Verstappen suffered more misery as he crashed out of Practice One.
Verstappen's difficult start to the season continued as he spun into the barriers after just 35 minutes of running.
The Dutchman had been leading the timesheet when he lost the rear of his Red Bull as he attempted to turn into Turn Six and was pitched into the wall.
Verstappen was unable to get his RB14 going again and had to watch the remainder of the session from the Red Bull garage, finishing sixth in the timesheet.
Bottas posted a 1:44.242 on ultrasoft tyres to top the timesheet in Baku by 0.035s from Chinese GP winner Daniel Ricciardo, although the Australian posted his best time on his third flying lap on the slower supersoft tyres.
Sergio Perez was third on an encouraging morning for Force India, while world champion Lewis Hamilton was fourth but nearly a second off the pace set by his Mercedes team-mate and Ricciardo.
"It's very encouraging for Bottas. He was very solid," Sky F1's Paul di Resta said.
"It's quite a mixed up finishing order. I think Ferrari will come to the party. Maybe teams are just focusing on different things at the moment until the track clears up because it was very dusty."
Ferrari also suffered a disappointing start to the weekend with neither of their drivers threatening the top of the timesheet.
Championship leader Sebastian Vettel was only 10th, 2.2 seconds off the pace, and the German regularly complained of lacking rear grip.
Team-mate Kimi Raikkonen was three tenths further back in 15th, and the Finn's session was brought to a premature end by a power unit problem.
Force India set the early marker to be 'best of the rest' this weekend with Perez third and Esteban Ocon fifth and 1.4 seconds ahead of Fernando Alonso's McLaren in seventh.
Williams also enjoyed their best session of the season so far with Sergey Sirotkin eighth, ahead of Pierre Gasly's Toro Rosso, with team-mate Lance Stroll - who finished third in Baku a year ago - 11th.
Reanult suffered a disrupted session with both Nico Hulkenberg (13th) and Carlos Sainz (20th) ending their sessions early after big lock-ups, while Haas failed to show the promise of the opening three rounds with Romain Grosjean 14th and Kevin Magnussen 18th.