SPA-FRANCORCHAMPS, Belgium -- Ferrari had beaten Mercedes to victories before this year, but Sunday's win at the Belgian Grand Prix was the most convincing so far. Sebastian Vettel finished the race 11 seconds clear of Hamilton, and while at least three of those seconds came in the final few laps once the Mercedes had backed off, Hamilton had no answer for Vettel during the most important stages of the race.
Perhaps it shouldn't have been a surprise. Ferrari has held a growing advantage over Mercedes since the British Grand Prix at the start of July, and at the last two rounds in Germany and Hungary, Hamilton won against the odds thanks to wet conditions either in the race or during qualifying. The result in Spa, therefore, could simply be seen as the start of a rebalancing in the championship in favour of the team with the faster car.
"I would say those last two races in particular, with the cards that we were dealt we did a better job even though they had better cards," Hamilton said on Sunday evening. "But there is only a certain amount of times you can do that. If you are playing with a deck of cards and you are bluffing there is only a certain amount of times that you can do that before your opponent realises."
The layout of the Spa-Francorchamps circuit was perfect for exposing the relative strengths and weaknesses of the two cars. Ferrari's package seemed almost tailor made for Spa's first and final sectors, with Vettel enjoying better traction out of the first corner at La Source and more grunt to pull him from the base of Eau Rouge to the next braking zone at the end of the Kemmel Straight. The same traits helped in the final sector, which consists of another long straight and a slow chicane at the very end of the lap, helping cement Ferrari's advantage over a complete lap of Spa in the dry.
Mercedes held the edge in the high-speed corners of the middle sector, but that was of little use once Vettel had used his car's strengths to get a better exit from La Source on the opening lap and power past Hamilton on the run to the next braking point at Les Combes.
"They have a power advantage," Mercedes team boss Toto Wolff admitted on Sunday evening. "We have seen that yesterday in qualifying, that power advantage is at various parts of the straights. You can see even if the exits are worse than ours, the engine keeps pulling.
"We can see they have a slight power advantage and then you add that to our weaknesses out of Turn 1 especially and that causes the doublewhammy. If you're not very good at traction and you're being outperformed slightly on power, that lap one happens."
The lack of traction created a downwards spiral in performance for Mercedes as it also left the rear tyres prone to overheating. The team ran more downforce than Ferrari to try to ease the strain on the rear tyres, but that also resulted in more drag, handing an even greater advantage to Ferrari on the straights.
At the end of the first stint of the race, there was clear blistering on Hamilton's super-soft tyres while Vettel's still looked in good shape. That meant Mercedes' hands were tied in terms of strategy and Ferrari was able to defend against a simple attempt at an undercut on lap 20. In every criterion required to have a quick car at Spa, Ferrari held the edge.
"Ultimately Ferrari did a better job all weekend, or they were just faster all weekend," Hamilton said on Sunday evening. "It's difficult to say they've done a better job, it's just that they were faster, simply faster. Their overall pace was stronger and I couldn't match it."
Is Ferrari's advantage locked in?
We've seen the balance of power swing between the two teams all season long, but Spa saw both teams introduce their third and final power unit update for the year. Any new hardware from this point onwards will result in a grid penalty, so the engine the two teams are running now will be the same one the drivers use until the end of the season. Mercedes was happy its upgrade brought the expected performance gains to Spa, but the only problem is Ferrari appeared to at least match that step with its own upgrade and, therefore, retain its overall advantage.
The exact details of how Ferrari is extracting so much performance from its power unit is still a mystery outside of Maranello. GPS data of the cars on track can trace the extra performance to areas where Ferrari is likely deploying electrical energy from its hybrid system, but how it was suddenly able to gain a significantly bigger boost than its rivals under the same set of regulations remains a subject of speculation.
The FIA conducted a thorough investigation into Ferrari's energy recovery system between the Azerbaijan and Monaco Grands Prix earlier this year. At the time it could not find anything untoward with the way it operated, and race director Charlie Whiting is still confident the system is legal following updates in the second half of the year. Wolff admits his team has questioned how Ferrari had found such significant gains, but insists he still has full confidence in the FIA.
"It is human nature that if you're being outperformed on track, you're looking at yourself where you are lacking and then it's looking at your competitors. And if you haven't got an explanation, you're trying to imagine all the nasty things. I haven't got any information, but I have real faith in the FIA.
"There's a great group of people around Olivier [Hulot, head of F1 electronics], Cedrik [Staudohar, F1 data analyst] and Nikolas [Tombazis, head of single seater technical matters] that are on top of things, that control every team and that are open minded and this is the case for all the teams. Everyone will try to innovate and find additional performance and they, the FIA, as far as I'm concerned, are doing the right things."
So now it's down to Mercedes to hit back, and Wolff is confident there is scope for his engineers to find more performance from its latest upgrade.
"It's all about understanding the new power unit, calibrating and extracting all of the performance out of the software, the fuels and the oils and optimising the way you run the engine. It's something that doesn't involve the hardware, and this is an ongoing process so the answer is yes, you can find performance.
"There is no silver bullet. We won't find any performance where it adds three tenths to the car or to the engine and then we disappear into the sunset."
Will Ferrari win in Monza?
On the face of it, Ferrari, with its power advantage over Mercedes, appears to be the favourite heading to its home race in Italy this weekend. Monza has been a Mercedes stronghold in Formula One since 2014, and even when Vettel came close to beating Hamilton in Spa last year, he was still some way off a week later in Italy. And despite Ferrari's stronger showing in Spa this year, Hamilton is confident Mercedes could still hold the edge on Ferrari's home turf.
"Luckily there, apart from Turn 1, it is not that slow, the chicanes. I'm hoping that the traction loss that we are having in the super slow corners here won't be so bad. The last two corners and Turn 1 is where we lose most of our time [at Spa].
"But also today, he [Vettel] didn't have to do any management. It was just flat chat and he didn't have the same problems with the tyres that I did. Hopefully that element is not a problem in the next race, but let's see."
Wolff is also intrigued to see how Monza pans out and believes it could act as a more useful barometer of performance for the remainder of the season.
"Spa was a tricky one for us in the past, but Monza was a good one, so I am very curious to see how it's going to go in Monza. Last year, we were very much in control of the whole weekend, Ferrari had their worst weekend of the season performance wise in so far, so I'm not worried.
"I think we should still address the opportunities that exist within our car, where we need to optimise and only that will make us win the championship."
After Vettel beat Hamilton at his home race in Silverstone and Hamilton returned the favour in Germany, the Italian Grand Prix is shaping up to be a real grudge match. A win for Ferrari will mean more than ever following the death of its chairman Sergio Marchionne last month, but Mercedes will not be in a charitable mood knowing its bogey track Singapore follows two weeks later.
Hamilton still holds a 17-point lead over Vettel in the drivers' championship, but with Ferrari's performance advantage that can easily be whittled awy over the remaining eight races. Mercedes has to hit back with performance upgrades soon and Wolff knows it.
"When I look at today's race, I see many deficits," he said. "We're a strong team and but there are deficits which are obvious, which cause us not to perform as we expect and insofar, it's not about someone else outperforming us, it's about us finding the clues to understand our underperformance."