Fernando Alonso got the most out of his Ferrari in Sunday's Belgian Grand Prix but it was not enough to beat Sebastian Vettel's dominant Red Bull and prevent him stretching his overall lead.

The Spaniard went from ninth on the starting grid to second at the finish but still Vettel surged 46 points clear at the top of the championship after his fifth win in 11 races.

"When they are dominating the weekend, when they do everything better than us and they win the race, they deserve the win," Alonso said.

"Weekends like this one we need to extract the maximum from the car. That is what we did this weekend, all we could in qualifying, all we could in the race.

"When you are the second fastest, you deserve to finish second," said the Ferrari driver, who moved up to second overall.

Next up is Ferrari's home race at Monza and Alonso said he would go there with more optimism than he had left the Hungarian Grand Prix before the August break, when he criticized his car's performance to the evident irritation of his team.

"In terms of the championship, we came from two fifth places in Hockenheim and Hungary, with a little bit of a not good feeling and not good performance from the car and today I think we recovered some of the optimism that we lost," he said.

"I think it was a good weekend for the championship in terms of feeling and in terms of points as well."

Alonso pointed out he was 41 points clear of Vettel last year after Monza and was 15 points behind by the time they arrived in Austin, Texas, for the penultimate race of the season.

He missed out by three points in the end.

"So things can change very quickly. Our hopes are to keep developing, to keep improving performance and try to repeat what happened last year the other way around," he said.

Qualifying remains a problem, and Alonso has not had a pole position since July 2012 or started on the front row of the grid in the past 21 races.

The Spaniard said that needed to improve, with Mercedes taking eight poles so far and Vettel the other three, but the championship was still open.

"To be honest, I'm doing what I can. I'm 8-3 against my teammate, I think," he said.

"Yesterday was about qualifying but I was 0.6 seconds quicker than my teammate. So in a way, it's not that the races are good and the qualifyings are bad, it's just the way it is and we are extracting the maximum from the car all the time.

"I think we are very strong. In the pure performance of the car, we are maybe lacking some performance compared to the others but I'm extremely happy with the performance we are achieving on Saturday and also on Sunday."