The church bells in Tavullia rang out on Sunday afternoon, as they always do when the town’s local hero wins a Grand Prix. I only know this because I watched the new MotoGP documentary Hitting the Apex last week.

The film’s advertised stars are Valentino Rossi, Jorge Lorenzo, Casey Stoner, Dani Pedrosa, Marc Márquez and Marco Simoncelli, but (in my mind at least), its greatest stars are Tavullia’s priests, Don Cesare Stefani and Don Giuseppe Signoretti.

The pair sit in their church (called, oh the irony, the Church of San Lorenzo the Martyr), remembering the last Saturday of June 2013, when they rang the bells to celebrate the Assen victory that marked Rossi’s return to the top step after two miserable seasons that were surely the beginning of his inevitable decline into retirement.

Once the bells were ringing (they are electronically operated, so no need for tiresome campanology) Don Cesare Stefani wandered off to join the wild celebrations at Rossi’s nearby pizza joint. There’s footage of the Bacchanalian goings-on, with Stefani (who looks uncannily like Grandpa Simpson) in the middle of it all, sipping wine. Only one problem: he’s enjoying himself so much he forgets about the bells, which continue pealing for the rest of the afternoon.

Any director given full access to Dorna’s best MotoGP footage would surely struggle to make a bad film. But Hitting the Apex (released in UK cinemas today, and worth seeing on the big screen) is a brilliant doc. It is probably motorcycling’s Senna.

Most of us already know much of the footage, but what makes the film, apart from the shepherds of the Tavullia flock, is the way director Mark Neale gets behind the scenes and drives the story forward. He transforms the four seasons from 2010 to 2013 and their background into a thrilling drama that seems like it was made for the movies. There are many moments that send a chill down your spine.

Rossi is the established king, mercilessly pursued by the five youngsters, who are all doing everything in their power to dethrone him. Their characters and the long, winding roads they’ve taken towards MotoGP are brought into focus – Lorenzo thrashing his minibike around a carpark in Majorca, Stoner bombing around dirt tracks in Australia.

Simoncelli looms large, as a lanky 12-year-old, looking ridiculously big on a minimoto, and later during his on-camera argument with Lorenzo on the eve of the 2011 Portuguese GP (“I will be arrested?”) and on to his horrible demise at Sepang five months later. Rossi speaks candidly about their friendship and how it ended.

The realities of the movie business mean that although the film has only just been released, it reaches its climax at the end of the 2013, with Márquez clinching his first MotoGP title at the last gasp and Rossi winning again, against all the odds.

And, of course, he’s still winning. Silverstone on Sunday was Rossi’s 112th GP win, which puts him a round 10 victories behind Giacomo Agostini’s all-time record. It was also undoubtedly one of his greatest and came 10 years after he won in similarly dismal conditions at Donington Park, astounding team-mate Colin Edwards.

The Texan was stunned by what he saw when he examined Rossi’s data. “I locked the front a couple of times and nearly crashed and it scared the shit out of me,” said Edwards, who finished fourth. “After the race I looked at his data and it was scary. The guy was locking the front on a track that was slicker than snot; he had it locked at every other corner. I asked him, was your front locked? He said, ‘oh yeah, a couple of times.’ I looked at the computer and it was, like, a couple of times? F***, it was every corner. This guy’s crazy!”

Rossi’s win at ice-like Donington was impressive, but winning a rain-lashed race at Silverstone is something else because the track is much faster, bumpier and scarier. The speed is immense, but it’s the bumps that are the real problem, especially in the wet, because they create puddles that can change the track every lap.

Rossi was able to deal with all that, riding so fast that Márquez crashed trying to keep up. And yet his last half-dozen laps – after Márquez had slid off at Copse – were the most impressive. During the final stages of the race the rain intensified once more. That made conditions even trickier, a situation further complicated by worn tyres. Rain tyres are at their best when the edges of the tread are nice and sharp. As the race goes on, the edges of tread get rounded off and the tyre loses much of its ability to cut through the water and grip the track.

That’s the reality Rossi faced as he dug deep to fight off a charging Danilo Petrucci, known for his speed in the wet, an ability which probably has something to do with the fact that the former Italian Superstock champion is MotoGP’s heaviest rider. More weight means more load through the tyres and therefore more grip.

Silverstone marked two-thirds distance in the championship: 12 races done, six to go. Rossi now stands 12 points ahead of Lorenzo who struggled to fourth on Sunday with a fogged visor.

If the Spaniard does lose the world championship due to a misted visor, he won’t be the first. In 1980 and 1981 Randy Mamola had his Nava mist up at numerous races, robbing him of the crown in least one of those seasons. Moral of this story: wear a decent helmet, no matter how much anyone is offering to pay you.

Rossi fans won’t like to hear this, but Lorenzo must be favourite to win the title, despite the 12-point disadvantage. On a normal day he is faster than his team-mate – even Rossi has admitted this on numerous occasions.

All Rossi can do is hope to do what he’s best at: pulling the rabbit from the hat, as he used to say. Sunday was one of those days. The rain gave him a chance he might otherwise not have had and he seized it with both hands. Another race or two out of the ordinary and he might just pull it off.

Rossi’s greatest allies over the next nine weeks are likely to be his crew chief Silvano Galbusera and reigning world champion Márquez.

Galbusera needs to find another tweak, like he did in June, when he prescribed a narrower front wheel rim (for better turning), which reignited Rossi’s championship hopes with that stunning victory at Assen. If Rossi can’t find any more speed out of his bike – engine, chassis and electronics – then he will struggle to hold off Lorenzo, who is unbeatable on his day.

And yet, and yet, there’s always Márquez, who will take more risks than ever to catch up in the points chase and may be the only rider capable of preventing Lorenzo from running away out front. If Márquez can do that, he will have to fight with his compatriot, and while they do that, Rossi may have a chance of catching them and racing with them.

Time will tell…