Ferrari F1 boss Mattiacci praises Raikkonen's drive in Brazil

The 2007 world champion has found Ferrari's 2014 F1 car difficult to drive for most of the year, and has usually been well-beaten by team-mate Fernando Alonso.

Raikkonen was the only driver to complete Sunday's Interlagos race on just two pitstops, and battled for sixth place with Alonso before finishing close behind him in seventh.

Mattiacci reckons Ferrari made a breakthrough in getting its car to suit Raikkonen's driving style.

"I think we have seen a very positive Kimi this weekend," Mattiacci said.

"He had a terrific race.

"I would say [this was] one of the first weekends where Kimi really felt the car suited him, and we have seen the way with [his] racing."

Mattiacci said the process of getting Ferrari's car to suit Raikkonen was ongoing, and denied the Finn still needed to raise his own game, despite another ultimate defeat to Alonso.

"Kimi is a top professional, [he] doesn't [need to] respond to positive pressure," Mattiacci added.

"We work well together. He's a top driver [and] we're building step-by-step preparing for the future.

"They [top drivers] know very well how to react to pressure.

"I'm extremely happy for the race he did."

Raikkonen reckoned he could have beaten Alonso to sixth without a delay at his second pitstop caused by damage to the front jack.

"I think we could have been one place better but we had some problems in the pitstop," Raikkonen said.

"I think over the whole weekend the car has been more normal and I could drive it more normally.

"It's definitely been better. My tyres lasted pretty well. It's going in the right way.

"There's still quite a bit of work to be done on the package, but we know that, and we're improving."