The 2014 title battle between Nico Rosberg and Lewis Hamilton, the Mercedes drivers, has officially turned nasty.
After the suspicions, claims and counter-claims surrounding Rosberg's off-track excursion in the dying seconds of qualifying for May's Monaco Grand Prix, the first real sign of inter-team dynamics turning sour at Mercedes, things became a little more blatant during Sunday's Hungarian Grand Prix.
Races are running out, time is ticking by, and the Silver Arrows drivers are no longer just scoring points to consolidate or improve their championship positions—they're scoring points against each other.
Their job, aside from winning races and recording podium finishes, is to act as an irritant to the man on the opposite side of the garage; to land a few cheap shots, to distract him and starve him of opportunities to gain the initiative.
Hamilton is arguably the most practiced of any driver in this style of warfare.
The 2008 world champion, prior to the Monaco weekend, told the official Formula One website that his relatively modest background in contrast to Rosberg's made him "hungrier" to succeed.
Ahead of Rosberg's home race at Hockenheim, Germany, meanwhile, Hamilton explained to Paul Weaver of The Guardian that his teammate was "not really German."
And you know what? Rosberg went on to win both those races.
A change of approach, then, was perhaps inevitable for Hamilton, who literally did his talking on the track at the halfway stage of the Hungarian Grand Prix.
The British driver, who with medium tyres fitted to his car was not planning to stop again, found himself ahead of a charging Rosberg, who had softer rubber and therefore one more trip to the pit lane to make, on Lap 46 of 70.
Hamilton, to make Rosberg's strategy work, was instructed via team radio to put up little resistance to his teammate's advances but, according to Sky Sports' Pete Gill, offered the reply: "I'm not slowing down for Nico. Get close and then he can overtake me."
He remained true to his word, keeping the German at arm's length for 10 laps—over which time Rosberg lapped consistently around a second slower than he previously had, according to the FIA's timing information—before the No. 6 car pitted for the final time on Lap 56.
Considering that Rosberg, according to the official F1 website, finished the race in fourth, only 6.3 seconds behind race winner Daniel Ricciardo, each of those seconds lost staring at Hamilton's gearbox were vital and could ultimately prove to be title-deciding ones.
For Hamilton, though, his stubborn—perhaps unprofessional—defiance had worked a treat.
Not only had he denied his teammate a potential fifth victory of the season, he ensured that he finished ahead of Rosberg, cutting the German's championship lead from 14 points to 11.
The slight erosion of Rosberg's advantage, though, was not achieved without a rather questionable defensive manoeuvre on the final lap.
Hamilton, slow on the exit of Turn 1 with 30-lap-old tyres, was under severe pressure from Rosberg heading toward the final genuine overtaking spot of the Hungaroring track.
Rosberg, like Ricciardo a matter of minutes earlier, took the outside line for Turn 2 and held it, finding traction before Hamilton edged across and ran his teammate out of road—to the point where the German dipped his front-right wheels on the grass, which would have been treacherously damp after the heavy pre-race rain shower.
Hamilton's conduct while fighting Rosberg at the Hungaroring was, more than anything else, a reflection of how tensions between the long-term friends have escalated over the course of the campaign.
Their battle in the Bahrain Grand Prix at the beginning of the season, for instance, was defined by its respectful, sporting nature, with both drivers leaving enough room for each other to ensure the wheel-to-wheel action lasted for an extended period of time.
Now the adrenaline has taken over. Now there is an urgency. Now there is an impatience, an intolerance, a selfishness.
There is little consideration for the wishes of their employers or the welfare of one another. The sense of enjoyment has been replaced by the need to succeed.
It's beginning to get personal between Hamilton and Rosberg—and we still have eight rounds to go.