Sochi, Russia - Championship leader Lewis Hamilton bounced back to top the times in Friday's second free practice session ahead of this weekend's inaugural Russian Grand Prix.
The 29-year-old Briton, who was second fastest behind his Mercedes team-mate and title rival German Nico Rosberg in the morning's opening session, wound up quickest in the afternoon with a dazzling lap of 1m39.630 seconds. He leads Rosberg by 10 points with four races remaining.
This was eight-tenths of a second faster than the chasing pack, led by Danish rookie Kevin Magnussen of McLaren, and made Hamilton the only man to go below the 1m40 barrier at the newly built track in the Olympic Park close to the Black Sea resort.
Two time champion Spaniard Fernando Alonso was third for Ferrari ahead of Rosberg, Finn Valtteri Bottas of Williams and Briton Jenson Button in the second McLaren.
Brazilian Felipe Massa, who had described last Sunday's Japanese Grand Prix as “the worst race of my life”, was seventh in the second Williams ahead of Red Bull-bound local hero Russian Daniil Kvyat of Toro Rosso and the man he is due to replace, four-times champion Sebastian Vettel.
Job hunting Frenchman Jean-Eric Vergne was 10th for Toro Rosso, turning in another impressive day's work as he seeks a new seat for 2015 after being released by his current outfit.
FIRST SESSION
Ferrari's Fernando Alonso was the first driver out of the pit lane when the green light came on, leading Force India's Nico Hulkenberg.
McLaren's Jenson Button was the early pacesetter as drivers got to grips with a layout compared to the former Valencia street circuit and Singapore, with the 2009 champion ending the morning as the third fastest.
He also collected two fines totalling €1100 (R15 400) for pitlane speeding.
Alonso was fourth with Danish rookie Kevin Magnussen, Button's team-mate, fifth.
The only Russian regular, Toro Rosso's 20-year-old rookie Daniil Kvyat, followed up seventh in the morning with eighth after lunch.
That was still ahead of both Red Bulls, his 2015 employers, with four times champion Sebastian Vettel ninth after reporting a loss of power on the straight and Ricciardo 13th.
He was joined for the first session by 19-year-old compatriot Sergey Sirotkin, making his debut at a race weekend in the Sauber usually driven by Mexican Esteban Gutierrez.
Williams had a disrupted opening session when a problem with a tyre blanket damaged a set of Valtteri Bottas's tyres, limiting his running.
All drivers took to the track with stickers of support for Jules Bianchi, Marussia's French driver who was severely injured in a crash in Japan last Sunday and remains in critical condition.
Marussia announced before the session that it would have only one car running this weekend, with Bianchi's assembled and left in the garage as a mark of respect.
Chilton ended the first session with the slowest time but picked up speed in the afternoon.
"I don't know how to put into words how truly devastated I am by what has happened to Jules," he had said before the session started.
"It is going to be a very emotional weekend for the whole team, but we will try to get through it and keep praying for Jules." - Reuters
RESULTS - FIRST SESSION
1 Nico Rosberg (Germany) Mercedes - 1m42.311s
2 Lewis Hamilton (Britain) Mercedes - 1:42.376
3 Jenson Button (Britain) McLaren - 1:42.507
4 Fernando Alonso (Spain) Ferrari - 1:42.720
5 Kevin Magnussen (Denmark) McLaren - 1:43.026
6 Sergio Perez (Mexico) Force India - 1:43.129
7 Daniil Kvyat (Russia) Toro Rosso - 1:43.164
8 Kimi Raikkonen (Finland) Ferrari - 1:43.212
9 Jean-Eric Vergne (France) Toro Rosso - 1:43.327
10 Valtteri Bottas (Finland) Williams - 1:43.542
11 Felipe Massa (Brazil) Williams - 1:43.741
12 Daniel Ricciardo (Australia) Red Bull - 1:43.821
13 Nico Huelkenberg (Germany) Force India - 1:43.976
14 Sebastian Vettel (Germany) Red Bull - 1:44.506
15 Adrian Sutil (Germany) Sauber - 1:44.625
16 Pastor Maldonado (Venezuela) Lotus - 1:44.876
17 Sergey Sirotkin (Russia) Sauber - 1:45.032
18 Romain Grosjean (France) Lotus - 1:45.190
19 Roberto Merhi (Spain) Caterham - 1:46.782
20 Marcus Ericsson (Sweden) Caterham - 1:46.922
21 Max Chilton (Britain) Marussia - 1:47.284
RESULTS - SECOND SESSION
1 Lewis Hamilton (Britain) Mercedes - 1m39.630s
2 Kevin Magnussen (Denmark) McLaren - 1:40.494
3 Fernando Alonso (Spain) Ferrari - 1:40.504
4 Nico Rosberg (Germany) Mercedes - 1:40.542
5 Valtteri Bottas (Finland) Williams - 1:40.573
6 Jenson Button (Britain) McLaren - 1:40.718
7 Felipe Massa (Brazil) Williams - 1:40.731
8 Daniil Kvyat (Russia) Toro Rosso - 1:41.108
9 Sebastian Vettel (Germany) Red Bull - 1:41.396
10 Jean-Eric Vergne (France) Toro Rosso - 1:41.531
11 Kimi Raikkonen (Finland) Ferrari - 1:41.630
12 Nico Huelkenberg (Germany) Force India - 1:41.677
13 Daniel Ricciardo (Australia) Red Bull - 1:42.061
14 Sergio Perez (Mexico) Force India - 1:42.090
15 Adrian Sutil (Germany) Sauber - 1:42.233
16 Romain Grosjean (France) Lotus - 1:42.892
17 Pastor Maldonado (Venezuela) Lotus - 1:42.905
18 Esteban Gutierrez (Mexico) Sauber - 1:43.055
19 Marcus Ericsson (Sweden) Caterham - 1:44.135
20. Max Chilton (Britain) Marussia - 1:44.530
21. Kamui Kobayashi (Japan) Caterham - 1:44.952