Alonso led Kimi Raikkonen's Lotus by as much as 12 seconds on his way to victory, while Sebastian Vettel's Red Bull fell half a minute behind.
Asked if the Barcelona result proved that this was his best shot at the Formula 1 title since joining Ferrari, Alonso argued that there was a lot more work for the team to do.
"Probably yes it is in terms of the performance of the car, although we should have won the championship in 2010 I believe, when we arrived in Abu Dhabi eight points ahead of Seb," he said.
"We lost there, it's nothing we can change now. Last year we didn't win - we were one second off, but we managed to fight until the Brazil race.
"This year we have a package that is still not the fastest but we are working on it.
"Definitely on Sundays it is a competitive team package. We are not the quickest over one lap, we maybe do not set the fastest time in the race, but we have fantastic pitstops, starts, tyre degradation... many ingredients to have a competitive car to fight for the championship.
"In many years in Ferrari it is true that we are the one to feel most confident but we are not happy with the performance, we want a good and aggressive development programme for the next races."
- Sports & Recreation
- Motor Racing
- Sebastian Vettel
- Kimi Raikkonen