Massa, who moved from Ferrari at the end of last year, completed 99 laps in the Mercedes-powered FW36 car and set the fastest time yet in seven days of testing at the Sakhir desert circuit.
"I'm really happy with the car and feel we found a good balance," said the 32-year-old, who carried out a full qualifying simulation on supersoft tyres towards the end of the afternoon.
"You can never be sure that you are 100 percent ready for the first race but I feel that what we have done in these days testing has been important for making sure that we have a car that can not only get to the end of the race but that will have good performance as well."
Vettel's car broke down with an electrical problem on its first lap out of the garage. He tried again later but only made it to the end of the pitlane before stopping again.
