In the end, literally, it was Vettel who won the title - beating Alonso by only three points - and set the bar high for that triple-champion record, earning his third straight title at 25 at the season-finale Brazilian Grand Prix in November 2012.
Vettel showed how, despite the previous two seasons of domination and then his Red Bull team's relatively weak start to 2012, he could still put together a string of impeccable performances late in the season to come from behind in the standings and win.
''If you contrast this with last year,'' said Martin Whitmarsh, the director of McLaren Mercedes, a rival team, ''when Sebastian had an incredible start to the season and had great momentum, and I guess you've got to say that it's impressive how he's come back this year and fought back into the position that he's in.''
He also had the pressure of trying to become only the third driver in history to win three consecutive titles, after Juan Manuel Fangio in the 1950s and Schumacher in the last decade.
''Correct me if I am wrong, but there are only two guys who have done that before,'' he said when an interviewer asked how he felt about that ''record.''
''You need to be in the right place at the right time,'' Vettel added, before saying: ''But I also believe you need to create your own luck.''
Alonso, for his part, drove one of the greatest seasons of his career and of any driver's career, taking several victories in a Ferrari that was not the best car. He hardly made a mistake all season, bringing the car to a top-three finish in most of the races that he failed to win.
''Fernando's season, in terms of maturity, in terms of driving, is really incredible,'' said Stefano Domenicali, the Ferrari director. ''I rate this season so far as one of the best of his career, considering the situation that he was in together with the team, at the beginning, above all.''
Alonso's tenacity and desire seemed to outweigh his chances, as when he proclaimed at the India Grand Prix in October that he was ''100 percent'' certain he would win the title, even though Vettel had taken the series lead.
Despite that optimism, Alonso is often dark, brooding, and taciturn, with a thick outer shell. Vettel is bright, cheerful, smiling, and gives long, well-thought-out responses to interviewers. Vettel can occasionally seem flippant, while Alonso is always deadly serious.
They also have different racing backgrounds. Coming from Spain, Alonso had no national racing heroes as role models. He was the first Spanish driver to win a Formula 1 race, let alone a championship.
He did not forge his path with the help of a rich family or in a young-driver support system, but rose on the basis of his results in the lower formulas and eventually with the backing of a powerful manager, Flavio Briatore. In the 1990s, the Italian had been director of the Benetton team, where Schumacher was driving when he scored his first two titles. Briatore later became director of the Renault team, where he hired Alonso to race in 2003.
Unlike Alonso, Vettel benefited from support from Red Bull before he even got to Formula 1. And Vettel had Schumacher as an example and personal mentor in Germany. He had even gone go-karting against his elder as a boy. Schumacher wished him luck before the Brazil race last weekend and said he was ''proud'' of Vettel.
Still, if Vettel benefited from the momentum of the Schumacher effect in Germany, that also might have been difficult to live up to for a driver of lesser talent and character. Vettel was even nicknamed ''Baby Schumi'' for his resemblance to the young Schumacher and his results.
But behind the differences in background and personality lie two huge driving talents and immensely ambitious drivers for whom victory is the only objective. Both showed that early in their Formula 1 careers in cars that were not quite ready for winning. Both started at the former Minardi team, which had trained many young drivers but always remained at the back of the grid. Alonso raced for the team in 2001 and Vettel in 2007, after it had been bought by Red Bull and renamed Toro Rosso. (Vettel had replaced another driver for one race at BMW Sauber the previous year before starting midway through 2007 at Toro Rosso.)
Alonso's first victory was at the Hungarian Grand Prix of 2003, when he became the youngest winner of a race, at 22. Vettel got his first victory in an opportunistic race in the wet at Monza at the Italian Grand Prix in 2008, beating Alonso's record as the youngest winner of a race at age 21.
Alonso has been criticized for requiring that a team surround only him and that his teammate be weak. This was partly due to a disastrous year on the human level at the McLaren Mercedes team in 2007, when he was teamed with Lewis Hamilton, who had been nurtured by the team since he was a boy. The two finished with an equal number of points, both losing the drivers' title by one point to Kimi Raikkonen at Ferrari. But since Alonso joined Ferrari in 2010, his teammate has been Felipe Massa, who also lost the title by only one point, in 2008 to Hamilton. Massa, who has been nurtured throughout his Formula One career by Ferrari, is not slow and Alonso has still overshadowed him.
Vettel has been criticized for needing all the cards - technically and in terms of starting a race from the front row - in his hands to perform well. But at the Abu Dhabi Grand Prix on Nov. 4 he was sent to the back of the starting grid after a technical infringement on the car, and he came back to finish third. He did nearly the same thing at the race in Brazil after being knocked into a spin by another driver at the start, and dropping to last place, but then finishing sixth, scoring enough points to beat Alonso, who finished second, for the world title.
So it has been a season that placed both drivers among the all-time greats. For the four-time champion Alain Prost, however, that is not quite true. When asked in an interview at the Abu Dhabi race to compare the current top drivers to those of his era, in the 1980s and early '90s, Prost said: ''They are unclassifiable, in the same way that we could not classify the drivers of my time by comparison to Fangio or Ascari. I find that the generation of these drivers is pretty exceptional. But to judge them or compare them, it's not possible. But it remains a really good crop, it's really very good.''