Lewis Hamilton's maiden shot at matching Michael Schumacher's victory record began by finishing a surprise last but one in opening practice for the Russian Grand Prix.
Hamilton moved to within one of Schumacher's 91 wins following his triumph in Mugello earlier this month.
But the six-time world champion was only 19th here at the Sochi Autodrom, 2.8 seconds slower than pace-setter Valtteri Bottas in the other Mercedes.
Daniel Ricciardo was second for Renault ahead of Red Bull's Max Verstappen on a morning disrupted by a number of accidents.
The most significant of which involved Nicholas Latifi. The rookie driver lost control of his Williams through the right-handed Turn 10 at the Sochi Autodrom, sliding backwards into the barriers.
Latifi sustained significant damage to his car but emerged unscathed from the heavy impact before the session was suspended to recover his stricken car.
Earlier, McLaren's Carlos Sainz also spun at the same corner, but the Spaniard was able to limp back to the pits, albeit without his broken rear wing.
Hamilton's chance of a quick lap was thwarted when he was caught out under braking for the opening corner.
Hamilton missed the apex of the right-handed bend before heading through the run-off area and aborting his lap.
For team-mate Bottas, who trails Hamilton in the championship standings by 55 points, there were no such concerns as he headed the time charts by 0.507sec.
The Finn has not won a race since the opening round of the campaign in Austria.
Elsewhere, Sergio Perez and Lance Stroll finished fourth and fifth respectively for Racing Point, with Sebastian Vettel ninth and Charles Leclerc 11th for Ferrari, while McLaren driver Lando Norris was 13th, two seconds down on Bottas.
The 10th round of the season is being played out in front of a significant number of spectators for the first time this year with 30,000 fans expected through the gates this weekend.