Lewis Hamilton looks poised to bring the fight to Nico Rosberg in qualifying for the Russian Grand Prix after topping the timesheets in Saturday practice.
Rosberg has opened up a 36-point advantage in the drivers' standings by winning the first three races of the season as world champion Hamilton has been dogged by reliability issues.
And though Hamilton looked quick in his qualification simulation laps, a shredded left-front super soft tyre could leave him short of strategy options come raceday.
It was not all plain sailing for Rosberg either, as he went off-track at turn 13, where Sergio Perez was also let down by a lack of grip at the Sochi Autodrom - a theme of the weekend so far.
Hamilton started the Chinese Grand Prix last time out from the back of the grid after his car failed him on Saturday and there was almost another shock as Sebastian Vettel was released from his pit box with the Brit charging down the pit lane.
Four-time world champion Vettel - who was third quickest but faces a five-place grid penalty after qualifying - slammed the brakes on, however, to keep both drivers on the road.
1 Lewis Hamilton (Mercedes) 1:36.403
2 Nico Rosberg (Mercedes) 1:36.471
3 Sebastian Vettel (Ferrari) 1:37.007
4 Kimi Raikkonen (Ferrari) 1:37.727
5 Felipe Massa (Williams) 1:37.918
6 Valtteri Bottas (Williams) 1:37.985
7 Max Verstappen (Toro Rosso) 1:38.133
8 Jenson Button (McLaren) 1:38.260
9 Carlos Sainz Jr (Toro Rosso) 1:38.465
10 Sergio Perez (Force India) 1:38.542