Valtteri Bottas set the fastest time of the final morning of testing as Red Bull's recovery was halted by a spin for Sebastian Vettel.
After Felipe Massa was quickest on the penultimate day, Bottas set a time of 1:34.797 to finish the morning session over 0.7s clear of Fernando Alonso. Bottas also completed 80 laps as Willams' extremely impressive end to testing continued.
Alonso set a time of 1:35.509 as Ferrari only managed 27 laps during the first four hours, just edging out Nico Hulkenberg's Force India by 0.068s. Jean-Eric Vergne was also within 0.2s of Alonso as Toro Rosso set the fastest time of the Renault-powered cars on Sunday morning, with the top four all covered by less than a second.
Vettel was recovering well from his wretched day on Saturday and had just completed 44 laps when he spun at Turn 1 to cause the first red flag of the morning. A small fire appeared to then break out at the rear of the Red Bull and Vettel was consigned to the garage for the final hour of the session.
Sauber was another team recovering from just a solitary lap on the penultimate day, with Adrian Sutil completing a mammoth 91 laps by the lunch break. He will hand over to team-mate Esteban Gutierrez for the afternoon having set the fifth fastest time with a 1:36.467.
Mercedes suffered another setback at the start of the day, with Lewis Hamilton failing to run until three and a half hours in to the session due to a gearbox issue. That followed a delayed start for Nico Rosberg on Saturday as the team had to make a precautionary engine change.
There was more strong mileage for Caterham as Kamui Kobayashi completed 58 laps, while Romain Grosjean had completed 25 laps for Lotus when he brought a slightly early end to the morning session by stopping on the exit of Turn 10.