Is Vettel's Ferrari honeymoon over?

While Lewis Hamilton further enhanced his championship credentials with a crushing victory in Sunday's Singapore Grand Prix, cracks began to appear in Sebastian Vettel's relationship with Ferrari. Rob Watts takes a look at the growing strain between Vettel and the Scuderia.

Hamilton's Singapore win, his seventh this year, was for many reasons one of the most significant of 2018. Ferrari arrived in the Lion City expecting to challenge for victory, and could easily have been labelled as favourites given Mercedes' troubles here in recent years.

But once again, the Silver Arrows more than maximised their package, allowing Hamilton to deliver the perfect pole lap and providing him the opportunity to control the race - which he did with devastating consequences for Vettel's title hopes.

In fact, although that mesmerising pole lap was crucial to Hamilton's success this weekend, Vettel had already been on the back foot entering qualifying due to an ill-timed error in Friday's second practice session.

A brush with the wall seemed innocuous enough at the time, but it lost Vettel crucial track time in the weekend's most representative practice session, held in conditions close to those the teams would experience during qualifying.

Vettel recovered to go quickest in FP3, but his lost track time a day earlier likely played a significant part in his failure to qualify alongside Hamilton on the front row.

As has been seen in recent Singapore Grands Prix, anything can happen during the race and Ferrari would have been confident of making up that deficit and taking the fight to Hamilton once more.

An early pass on Max Verstappen seemingly put Vettel back in position to do just that, but Ferrari's decision to go for the undercut on Hamilton proved to be their undoing.

VETTEL: "Overall, we were not fast enough. We tried to be aggressive in the beginning, and it didn't work out" #SingaporeGP ???????? #F1 pic.twitter.com/7hSHKcQdLm — Formula 1 (@F1) September 16, 2018

It's understandable that Ferrari wanted to put the pressure on Hamilton by adopting an aggressive strategy early in the race, but the decision to switch Vettel to the ultrasoft tyre was unexpected, verging on bizarre, and left him with an uphill task for the remainder of the race.

Needing to pump in a series of quick laps to capitalise on his fresher, softer tyres, neither Vettel nor the Ferrari pit wall anticipated getting stuck behind the Force India of Sergio Perez. A frustrating few laps lost the German valuable time while Verstappen's pace in front was good enough to see him pit and re-join narrowly ahead of Vettel.

Should Ferrari have anticipated the risk of being stuck behind Perez? Switching to ultrasofts was a bold move, but relied on Vettel being able to pass and take advantage on a clear track. At a street circuit like Singapore, that was always a risky strategy.

The undercut hadn't worked, and Vettel's frustrated radio calls left us in no doubt as to his feelings on the strategy he'd been placed on.

"There is no chance, we're again too late," Vettel said. "These tyres will not make it to the end."

As it happens, they did last, but at the detriment of performance.

Vettel slipped from around 10 seconds off the lead with 15 laps remaining to almost 40 at the flag.

Verstappen, on the same soft tyre as Hamilton, was able to apply pressure as the lead pair began to lap backmarkers, but Vettel was left behind and seemed to back off altogether towards the end of the race as it became clear his Ferrari could not keep up.

A 40-point lead with 6 races left

Can @LewisHamilton be caught? ????

#SingaporeGP ???????? #F1 pic.twitter.com/LH7hIi1Ttg — Formula 1 (@F1) September 16, 2018

Vettel defended his team after the race, but the harsh truth is that Ferrari have once again conceded ground to Mercedes and Hamilton when they had a car capable of taking the spoils.

Despite having the quickest car at several races this season - and operating at a more consistent level than during their up and down 2017 campaign - Ferrari's 11-year wait for another world drivers' championship looks set to continue.

Hamilton believes luck has played no part in his recent run of four wins from five races, but rather that he and his Mercedes team have dealt with the pressure much better than Vettel and Ferrari have at crucial moments.

It's hard to argue with him. Vettel has made several costly errors this season, notably at the Azerbaijan, French and German Grands Prix, while he has been at odds with Ferrari's strategy calls on several occasions, which implies a lack of confidence in his team.

Vettel's peaks have been as good this season as at any point during his near four years at Ferrari, but the fact of the matter is Hamilton has much fewer off days and that has once again led him to seize control of the title race heading into the final leg of another long and tiring campaign.

As another world title appears to be slipping from his grasp, Vettel's Ferrari career is in danger of heading the same way as Fernando Alonso's fruitless spell with the Scuderia. Whichever way you look at it, Ferrari's inability to consistently beat Mercedes combined with Vettel's momentary lapses of concentration have placed both on the verge of another season of failure.

With Ferrari making the bold move to employ the inexperienced Charles Leclerc next season - the team's youngest race driver since the 1960s - the pressure will only increase further on Vettel should the Monegasque driver hit the ground running and position himself as more than just an able rear gunner to Ferrari's star man.

Whatever happens between now and the end of the season, Vettel must lay down a marker for 2019, and make it clear to incoming Ferrari chief Louis Camilleri that he is very much still the man to lead the Scuderia's charge in seasons to come.

Vettel's dream of becoming a world champion with Ferrari may not be over, but there are signs that the honeymoon period he has enjoyed since joining may soon be.