Barcelona: World champion Lewis Hamilton was fastest on a rain-interrupted first morning of the final four-day test in Barcelona.
Hamilton bettered his own time that sealed pole at the Spanish Grand Prix last year in 1min 24:881sec within the first hour, but was held up by an unexpected rain shower that limited the Englishman to 48 laps.
Felipe Massa was second quickest for Williams, whilst Daniil Kyvat was third fastest despite breaking down in the Red Bull on his way out the pitlane early on.
However, McLaren-Honda`s problems persist as Jenson Button was once again at the back of the grid on time and mileage completed after completing just seven laps.
Force India weren`t in action as the Silverstone-based team hope to run their new JVM08 car for the first time on Friday afternoon.
Results from the morning session on day one of the third pre-season test in Barcelona:
1. Lewis Hamilton (GBR/Mercedes) 1:24.881 (48 laps)
2. Felipe Massa (BRA/Williams) 1:25.763 (29 laps)
3. Daniil Kyvat (RUS/Red Bull) 1:25.947 (45 laps)
4. Romain Grosjean (FRA/Lotus) 1:27.079 (33 laps)
5. Marcus Ericsson (SWE/Sauber) 1:27.802 (33 laps)
6. Kimi Raikkonen (FIN/Ferrari) 1:27.813 (28 laps)
7. Carlos Sainz Junior (ESP/Toro Rosso) 1:27.866 (34 laps)
8. Jenson Button (GBR/McLaren) 1:31.479 (7 laps)