Frederic Vasseur has hailed the performance of Sauber rookie Charles Leclerc in Baku.

After a difficult start to 2018, the much-feted Ferrari junior and reigning Formula 2 champion finally broke through with an impressive run to sixth place.

Asked if the performance surprised him, Sauber boss Vasseur told Auto Hebdo: "No.

"On Saturday he excelled in qualifying and felt confident about the race. He also showed good pace on Friday and knew that he had good prospects."

Vasseur said that the 20-year-old Monaco-born driver's performance came at a good moment.

"Yes, this result will allow him to feel confident after an unsuccessful start to the season," said the Frenchman.

"It's the same for the team. It's good for the confidence and motivation of everyone, even if we have to keep moving gradually."

However, he warned that it could be a different story at the next circuit, Barcelona.

"Baku suited our car because of the low drag, favouring a very powerful engine with not much downforce. But the next weekend in Barcelona will be different.

"We must wait for Canada, as that is a track more suitable for our car again."

Sauber are ninth in the constructors' standings ahead of the Spanish Grand Prix.