Ferrari's Kimi Raikkonen just edged Renault driver Giancarlo Fisichella to finish on top of the times on the final day of testing at the Paul Ricard circuit.
The Finn posted a best time of 1:28.624 to finish as quickest for the second day running.
Raikkonen enjoyed a more productive day than yesterday, when he was hit by an electronic problem that cut his running short.
The Ferrari driver covered over 100 laps today as the Italian squad continued with their preparations for the Canadian Grand Prix next month, working around 5.2-km 1E layout of the circuit.
On a sunny day at the French circuit, Fisichella finished less than 0.020 seconds behind Raikkonen after 111 laps with his Renault.
Spaniard Pedro de la Rosa was third quickest for the McLaren-Mercedes team, despite his three-day old engine expiring around noon.
There were another two red flags during the day, the first caused by Spyker's Adrian Sutil, who stopped on track at 10:40am, and the final one triggered by Jenson Button, whose Honda engine let go with 50 minutes of the session remaining.
Frenchman Franck Montagny completed a positive four-day test for the Toyota team with the fourth fastest time, ahead of Williams' test driver Kazuki Nakajima.
David Coulthard completed 77 laps on his way to the sixth quickest time of the day, his Red Bull team carrying out high and low downforce set-up work.
"I did high downforce work in the morning, something we could not do yesterday, and low down force work in the afternoon," Coulthard told autosport.com. "We tried both tyres, so we will see how they will behave in Monaco. It's very difficult to simulate Monaco anywhere so we will find out in a few days."
Briton James Rossiter was the busiest man on track as he completed 131 laps of the French track to wrap up his maiden test with the Super Aguri team.
BMW Sauber's Nick Heidfeld took over from teammate Robert Kubica as the German squad worked on optimising their set-up for low and medium downforce tracks. Heidfeld finished the day as ninth fastest.
"The car seems okay in low downforce and I was doing some work left over from yesterday," Heidfeld told autosport.com. "I also tried Montreal wing configurations and it is hard to tell but the (wind tunnel) numbers are okay and from a driver's side the feeling is okay.
"It is just that this track in not Montreal and Monaco, so it's hard to judge."
Pos Driver Team Time Laps 1. Raikkonen Ferrari (B) 1:28.624 101 2. Fisichella Renault (B) 1:28.641 111 3. de la Rosa McLaren-Mercedes (B) 1:29.249 78 4. Montagny Toyota (B) 1:29.312 79 5. Nakajima Williams-Toyota (B) 1:29.631 100 6. Coulthard Red Bull-Renault (B) 1:29.834 77 7. Rossiter Super Aguri-Honda (B) 1:29.869 131 8. Sutil Spyker-Ferrari (B) 1:29.869 83 9. Heidfeld BMW-Sauber (B) 1:29.978 118 10. Button Honda (B) 1:29.989 100 11. Liuzzi Toro Rosso-Ferrari (B) 1:29.993 56 All Timing Unofficial