Lewis Hamilton maintained his strong form by setting the quickest time during the second practice session for the European Grand Prix at the Baku City Circuit.
Hamilton was on course for the fastest time until a mistake at Turn 16 on his first flying lap, but he regrouped on his second attempt to record a time of 1:44.223 on the Super Soft tyres.
Hamilton’s best time was 0.690s clear of Mercedes team-mate Nico Rosberg, as the reigning World Champions finished comfortably quickest in Azerbaijan.
However, it wasn’t the smoothest day for Mercedes as Rosberg stopped on track with 20 minutes remaining, complaining of a “problem with the drive and the engine.”
Sergio Pérez was third quickest for Force India, 1.113s down on Hamilton, with Valtteri Bottas in fourth and Nico Hülkenberg fifth.
Carlos Sainz Jr. was the fastest non-Mercedes powered runner in sixth position, albeit 1.804s adrift of Hamilton’s best effort.
Max Verstappen was seventh for Red Bull with Sebastian Vettel the lead Ferrari driver in a low-key eighth place, before he was told to return to the pits at slow speed during the closing minutes.
Jenson Button was ninth as Red Bull repaired Daniel Ricciardo’s car following his crash in the first session, enabling the Australian to round out the top 10.
McLaren’s Fernando Alonso was 11th despite a problem with his engine, which forced him to crawl back to the pits, while Romain Grosjean was 12th for Haas.
Kimi Räikkönen was a lowly 13th for Ferrari and stopped on track with five minutes remaining after his rear tyres appeared to lock on the approach to Turn 4.
Toro Rosso’s Daniil Kvyat was 14th, ahead of Haas’ Esteban Gutiérrez, who brushed the barriers exiting the narrow Turn 8.
Williams’ Felipe Massa collected 16th position, in front of Kevin Magnussen, Rio Haryanto and Marcus Ericsson, who missed the opening stages of the session after a power unit change.
Renault's Jolyon Palmer, Manor's Pascal Wehrlein and Sauber's Felipe Nasr completed the field.
Several drivers had off-track excursions, most prominently at Turns 1 and 15, as they got to grips with the circuit, but were all able to re-join without damage.