It's been Lewis Hamilton and Sebastian Vettel vying for world championships in most of the last nine seasons. Hamilton now has five titles to Vettel's four, and the German's error-prone season doesn't bode well for Ferrari in 2019.

Hamilton delivered a series of vintage performances this year: besting Kimi Raikkonen one-on-one in Ferrari's backyard in Monza, recovering from 14th on the grid to win on Vettel's home turf in Germany, delivering a qualifying lap for the ages to claim pole and later the win in Singapore, and looking imperious all weekend at Japan's technical and challenging Suzuka circuit. As Hamilton's form improved, Vettel's dropped off; a tight title race morphed into a bit of a walkover.

But in many ways, Hamilton's career is better defined by its connection to another, less decorated rival — Fernando Alonso.

Back in 2007, few would have given the rookie British driver any chance of keeping pace against a 26-year-old Alonso. The Spaniard was the 2005 and 2006 world champion — the youngest in the sport's history until Vettel came along — and the man who had just brought a decade of Michael Schumacher dominance to a shuddering halt.

'He showed talent from day 1'

But, as Alonso himself said earlier this month, Hamilton "showed talent from day 1." He finished on the podium in his first ever grand prix and within six races, he'd picked up a pole position and a win. Most astonishingly of all, it took 10 races until Hamilton finally failed to finish in the top three.

Hamilton became such a threat to Alonso in 2007 that the two really couldn't co-exist at McLaren. Team boss Ron Dennis didn't want to stifle Hamilton's fairy-tale rookie season, while Alonso felt he wasn't getting the team-leader treatment he'd been promised when signing up as the hottest property on the grid.

An amusing commercial for team sponsor Santander — depicting Hamilton and Alonso racing to be first to get from the track to their hotel rooms, all to the tune of "Anything you can do, I can do better" — was just a little too on-the-nose. The uneasy alliance couldn't last. 

The upshot — virtually unthinkable 12 years ago — is Fernando Alonso retiring from F1 with just the 2005 and 2006 championships to his name, as Lewis Hamilton claims his fifth drivers' title.

'Probably Michael, Fangio, Senna, Prost, Lewis'

Alonso, asked to rank his F1 top five, included the man who scuppered his shot at a spot among the most successful in the sport — choosing Michael Schumacher, Juan-Manuel Fangio, Ayrton Senna, Alain Prost and Hamilton.

It's extremely difficult to argue with this selection, despite other strong candidates. Perhaps Jim Clark had the potential to join this exalted company, but for his untimely death at Hockenheim in 1968. Some might argue for Fangio's great 1950s rival Stirling Moss, five times a championship runner-up. Niki Lauda won three titles despite his life-threatening crash, even while taking a four-year break from F1 in his prime.

And a few could ask what might have been for the man from Oviedo, if Hamilton had never joined Alonso at McLaren.

'Arguably the greatest I've driven against'

Hamilton himself hinted at this when Alonso announced his retirement from F1 earlier this season, saying Alonso was probably the best driver he'd ever competed against, and that he deserved greater success in the sport. Never shy of lacing his compliments with some criticism, the Brit also suggested Alonso perhaps wasn't as sly or as shrewd outside the cockpit as he was speedy behind the wheel.

"It's not just about being a great driver it's also how you maneuver, how you play the game," Hamilton said. "Like a chess game, it's how you position yourself — all these different things that are also part of the package."

In 12 seasons on the grid, Hamilton has shown this mix of pure pace and political guile. Moving to Mercedes from McLaren ready for the 2013 campaign seemed a bold if not suicidal career move at the time; six seasons and four world titles later, it looks like a stroke of genius.

But to this day, the damage Hamilton did to Fernando Alonso's F1 legacy remains perhaps the best indicator of his impact on the sport.