Was Hamilton fair to Rosberg?

Lewis Hamilton had Nico Rosberg on the ropes just seconds into the Japanese Grand Prix, and he knew it.

He'd negated his team-mate's pole position advantage in a matter of metres, and while Rosberg was trying to hang on around the outside of Suzuka's infamous first turn, he was trapped. Deep breaths in both cockpits. Who would yield?

Sensing the moment of truth would come on the exit of Turn 2, Hamilton accelerated through that second right-hander, maintaining firm position on the inside, a line he knew would carry his car out towards the racing line on a slightly straighter trajectory than usual.

Rosberg found himself squeezed over the kerb on the outside then off the circuit. As he scrabbled for traction on the gripless green artificial grass, he slipped back to fourth, behind Sebastian Vettel's fast-starting Ferrari and the lead Williams of Valtteri Bottas. Game, set and match Hamilton.

Rosberg has made much of the fact he has become a better racer in Formula 1 this season, how he's had to become a better racer in order to carry the fight to Mercedes team-mate Hamilton in the world championship.

He knew he badly needed to win this grand prix. His chances of winning this year's title have been slipping slowly away by the race, while Hamilton has seemingly been marching inexorably towards a third crown. Rosberg needed to strike back, and strike back hard.

After being slower than Hamilton away from the grid, Rosberg had to react quickly. The entire destiny of the race, even his fading championship dream, was on the line. With Hamilton on the attack, would this be the moment that Rosberg bared his teeth, showed the world his true racer's steel, refuse to yield at the crucial moment?

Having failing to qualify on pole for only the third time this year, Hamilton wasn't really sure how he would turn a losing position into victory here.

"That's the million dollar question," he said after qualifying. "I don't know. You have a chance at the start, there's not a big chance on the strategy but it's not impossible. You could potentially offset your tyres maybe.

"You can't overtake here, pretty much. It doesn't matter how good you are, you can't get close enough, because the guy in front is going to have the clean air."

After acing that start on Sunday, Hamilton instinctively sensed his big chance. He generated superior momentum despite starting on the dirty side of the grid, and with it came the opportunity to remind everyone that he, not Rosberg, is the best racer within the Mercedes team - the man with that extra little something to get the job done when it really counts.

Ultimately it was Hamilton who won out yet again.

"It was a battle round Turn 1 and 2," said Rosberg. "It got very close on exit of Turn 2, so I had to back out of it - and that lost me the race. I've not seen it on TV, but it was close. I had to avoid a collision."

"The inside line is the inside line so it was my corner," explained Hamilton. "We were very close. I was understeering, running out of grip. I imagine Nico ran out of road, but that's what happens when you're on the outside."

Motor racing is a team sport, yes, but it is also a truly selfish pursuit at its core. When drivers are fighting over the same piece of road for the high-stakes rewards of race wins and championships, allegiances, etiquette, sportsmanship, and even friendships can count for nothing in those split-second moments of decision. If easing another car off the track is necessary to ensure you win the race then so be it.

In the recent past the FIA has come down hard on drivers who don't give their rivals enough space while overtaking or being overtaken.

At Monza last year Kevin Magnussen was penalised five seconds for forcing Valtteri Bottas off the track at the first chicane as they fought over fifth place. On that occasion the stewards felt Magnussen deliberately didn't give his rival sufficient room while defending position, and you could argue Hamilton did exactly the same to Rosberg in attack here.

Theoretically there is enough room for both cars to come out of Turn 2 side-by-side and continue their fight into the first part of the S curves. That's not what happened on this occasion, but to give Rosberg more racing room on the exit would have required an act of generosity that Hamilton was understandably unwilling (and possibly unable given the understeer he mentioned) to make, given the reward on offer.

Ultimately Rosberg didn't dwell on the fact, and the stewards (including five-time Le Mans 24 Hours winner Emanuele Pirro) saw no reason to act or even to investigate what happened. What Hamilton did was just a normal part of the game. If it made the difference between winning and losing the race, every racing driver on the planet would likely have done exactly the same thing.

Such was Mercedes' renewed superiority around Suzuka that Rosberg was still able to recover to second place, passing Bottas at the final chicane on lap 17 of 53 then jumping Vettel's Ferrari with an earlier second pitstop on lap 29.

Rosberg seemed fairly sanguine about the whole affair afterwards, but perhaps the bigger question is whether this latest defeat, and in particular the manner of it, is indicative of a wider problem for his ambitions of becoming champion, either now or in future seasons.

This was another grand prix where the two Mercedes went wheel-to-wheel and Rosberg came off second best. We have yet to witness a race in the V6 hybrid turbo era where Rosberg has been able to overtake Hamilton and make it stick. Sure he 'overtook' Hamilton off the startline to win in Austria, but he didn't have to fight for it - he was ahead well before they reached Turn 1.

What we witnessed in Japan was a proper exchange, a tense moment between team-mates and title rivals. One wonders if Spa 2014 still plays on Rosberg's mind, knowing the potential public furore and internal strife that would surely resurface should he again collide with Hamilton unnecessarily. Rosberg admits Spa was a tough learning experience for him last year. Perhaps the fallout has slightly softened his approach to combat, caused him to second-guess himself; to go a bit soft maybe?

"I don't think it has anything to do with him being soft or not," countered Mercedes team boss Toto Wolff.

"It's always very difficult to race your team-mate. We've seen some great overtaking afterwards against Bottas. It was a tricky situation for both. Lewis said he had understeer with the car, and two cars side-by-side through Turn 2 is difficult anyway."

Yet there still appears to be a trend of Hamilton being able to assert himself over Rosberg in battle, but not the other way around.

"Yes we have seen races like Bahrain and Spa [in 2014] where we have seen that, but it also shows how close they fight with each other, and I wouldn't want to say there is a tendency that if they fight it is Lewis who comes out with the better end [result]," Wolff added. "That's definitely not the case for me."

In fairness to Rosberg, there is a suspicion he might also have been fighting this particular battle with one hand tied behind his back.

Mercedes technical chief Paddy Lowe suggested the lack of dry running on Friday meant Mercedes slightly misjudged its cooling levels for this weekend, which caused both engines to overheat at different points in the race.

Wolff revealed afterwards that this problem struck Rosberg's car on the formation lap, which robbed him of crucial power after the start.

"The initial getaway was good for both cars but Nico had a little bit of an issue with a hotter power unit, and when it kicked in after a couple of seconds he didn't have the same power as Lewis," Wolff explained.

"This is temperature related. That was showing up on the formation lap. We don't know whether it is down to driver or the car, [but] that affected him for the fight into Turn 1, and Turn 2, maybe."

Given that drivers must now manage their car's settings for the formation lap and start without help from the pitwall, it is possible something in Rosberg's procedure differed to Hamilton's, or produced a different result, and on this occasion cost him dearly.

"It is important to get the clutch and engine into the right temperature window, particularly the clutch," Wolff added. "The driver manages that on the installation lap. So they are different procedures. Today that lap triggered different temperatures in the power units."

As he made his final pitstop on lap 31, Hamilton complained over the radio that his own car was "getting very hot", but he still enjoyed a substantial pace advantage over his team-mate during the final part of the race, when both cars were running one-two again.

"We had some minor drama with the car - temperature related issues," confirmed Wolff. "Lewis [also] flat-spotted his tyre [before the final stop] and that caused massive vibrations. When we took the tyre off the car, it was flat-spotted down to the carcass, so that could have ended badly.

"We tweaked the power unit and chassis a lot because we were seeing signs of reliability issues, which worried us a bit."

Rosberg initially pegged the gap at around 10 seconds during the first part of the final stint, lapping only 0.096s per lap slower on average than Hamilton from lap 33 (the Brit's first proper flier following his final stop) until lap 39. Then Hamilton turned the screw, lapping 0.643s faster than Rosberg on average over the remainder of the 53-lap race.

Singapore winner Vettel was another 0.010s per lap slower on average, having been over a second faster than Rosberg's Mercedes in the closing stages of the previous race. Hamilton's fastest lap in Japan was quicker than Rosberg's by a similar margin.

"It was such an amazing race," said Hamilton, who in winning equalled his hero Ayrton Senna in the all time list of F1 race victors by notching the 41st grand prix win of his career. "This has been a circuit ever since I've been coming here where I've struggled, but one I love driving.

"The car was better today than in qualifying. I worked on my lines and improved, and it was like sailing going through the corners."

A return to a conventional circuit, where efficient downforce and peak engine power again dominated the competitive equation, meant Mercedes was always likely to return to a winning position, following the travails of Singapore the previous week.

Even with both cars hampered by overheating engines, Mercedes was a clear step ahead of all its rivals, thriving on the harder tyre compounds its car uses so well.

"We've been doing a lot of work. We don't assume we should have gone to Singapore and won the race, even if we got everything right," said Lowe. "Ferrari and Red Bull are pushing hard and are strong competitors.

"Singapore was the most marginal circuit for us last year, so we can't assume we would come back and be dominant there. We don't optimise our car for Singapore - it's a high-downforce, drag sensitive circuit. We look for efficiency.

"The aero quota is restrictive today, so we don't spend [windtunnel] time on specific circuits. Others might have a different philosophy."

Mercedes' philosophy certainly paid dividends at Suzuka, putting the W06 firmly back on top of the competitive pile. The question now is whether Rosberg can do anything to arrest Hamilton's momentum in the championship race.

One thing is for sure: Hamilton will certainly not cut him any slack.