Lewis Hamilton recorded the fastest time on Saturday morning on the third day of pre-season testing at the Catalunya Circuit in Barcelona.
The British Mercedes driver, world champion in 2008, posted a quickest time of 1min 20.55sec on a dry track, over a second faster than Mexican Sergio Perez's fastest lap on the same circuit a week ago.
Germany's Adrian Sutil was second-fastest in a time of 1min 21.627sec in his Force India, while Brazil's Felipe Massa was third in a Ferrari.
Quickest on Friday, France's Romain Grosjean did not take to the track on Saturday morning but was due to participate in the afternoon session.
The four-day testing session ends on Sunday ahead of the start of the 2013 season in Melbourne on March 17.
1. Lewis Hamilton (GBR/Mercedes) 1:20.550, 2. Adrian Sutil (GER/Force India-Mercedes) 1:21.627, 3. Felipe Massa (BRA/Ferrari) 1:21.673, 4. Pastor Maldonado (VEN/Williams-Renault) 1:22.305, 5. Esteban Gutierrez (MEX/Sauber-Ferrari) 1:22.553, 6. Sergio Perez (MEX/McLaren-Mercedes) 1:22.694, 7. Mark Webber (AUS/Red Bull-Renault) 1:23.116, 8. Jean-Eric Vergne (FRA/Toro Rosso-Ferrari) 1:23.223, 9. Davide Valsecchi (ITA/Lotus-Renault) 1:23.448, 10. Jules Bianchi (FRA/Marussia-Cosworth) 1:24.307, 11. Giedo van der Garde (NED/Caterham-Renault) 1:24.520