Sir Lewis Hamilton and Fernando Alonso are two drivers who know each other very well, and their relationship has always been a fascinating one.
Their first experience of one another on a Formula 1 racetrack was in 2007, when Hamilton made his debut for McLaren.
They both won four races that year as they challenged for the title and, determined to get the edge over the young upstart, Alonso reached into his bag of tricks in an attempt to beat him to the crown.
The most memorable and controversial incident between the pair took place at the Hungarian Grand Prix that season, when the Spaniard deliberately stopped in the pit box ahead of his final qualifying run, denying Hamilton the chance to get back out on track.
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Eventually, they finished the season level on points, only to lose out to Ferrari’s Kimi Raikkonen by a single point at the Brazilian Grand Prix.
Since then, the pair have won 112 races between them, and they have met on the track a few times too.
Some exceptional wheel-to-wheel battles have been mixed in with some less than pretty moments – collisions in Bahrain in 2008, as well as a clumsy looking incident in Malaysia in 2011 spring to mind.
There was needle at the Hungarian Grand Prix last year too, when the 41-year-old defended valiantly to help team-mate Esteban Ocon win the race for Alpine.
Fast forward to this season, and the two world champions came to blows at last weekend’s Belgian Grand Prix.
Having passed Alonso off the start, the 37-year-old was unaware that the Alpine driver was back down his inside going into Les Combes, and he turned into the apex, only to find that the double world champion was already there.
The pair collided, sending Hamilton up into the air, and the car came down with some force, damaging the floor and the gearbox.
The seven-time champion was forced to retire, and he later made his way back to the media pen and conceded that the incident was “my fault.”
Alonso was not impressed. He labelled his former team-mate an “idiot” on the radio, and wagged his finger at him while passing his stricken Mercedes under Safety Car conditions on the second lap.
The Spaniard had calmed down afterwards though and, while maintaining that he was not to blame, he conceded that the crash was an easy one to have on the opening lap.
If we cast our minds back to a similar incident five years ago, Stoffel Vandoorne turned in when being passed by Felipe Massa at the Spanish Grand Prix, sending him out of the race.
Massa was unaffected, and he finished 12th, but the Belgian was still penalised for the next race in Monaco, where he crashed again while being passed by Sergio Perez having crashed in qualifying too – not a great couple of weeks for the now Formula E champion.
The former McLaren racer is an example of how things can change in Formula 1, but what generally has not changed is the stewards’ attitudes to first lap collisions.
In Spain that year, Max Verstappen, Valtteri Bottas and Kimi Raikkonen all got squeezed into the apex of Turn One, with the Red Bull and the Ferrari retiring as a result – no penalties were hand out.
Max Verstappen collided with Sebastian Vettel and Kimi Raikkonen at Spa six years ago, and he felt as though the Ferrari pair had turned in and hit him.
No penalties were given out due to the fact that 22 cars were barrelling in towards Turn One.
Would a penalty have been handed out if Hamilton and Alonso had suffered that same crash later on in the race?
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One could certainly argue that their attention would be more focused after the melee of lap one, so perhaps not, but this is trivial.
The incident took place on the opening lap, with Alonso going on to take P5 as the Briton failed to finish.
As a result, the stewards made the right call not to dish out a penalty to either driver in Belgium.