Mark Webber blasted Fernando Alonso for his "embarrassing" antics when battling Lewis Hamilton at the Abu Dhabi Grand Prix.
They are the two oldest drivers on the grid and share nine world championship successes between them. But there was still some petulance on show during the final race of the season when they came across each other on track.
Alonso came out of the pits to find the Mercedes racer behind him. On the approach to turn five, the Spaniard braked much earlier than expected which left Hamilton angry and confused.
He accused the Aston Martin driver of brake-testing him. And while the stewards did take a brief look at the incident over potential erratic driving on Alonso's part, they decided it was not worthy of investigation.
Alonso, 42, said after the race he had been trying to get Hamilton to overtake just before the DRS activation line so that he would have extra speed down the long straight that followed. "We did the same in Canada, I think, in 2012," he told reporters.
"So 11 years after that episode, we try just to give the DRS to the other guy, braking for turn five. But in both cases, I won. So it's okay. Obviously Lewis is very clever, understands the sport really good and has a lot of experience. But I have more."
But even though the move did not cause a collision, former Red Bull racer Webber was left unimpressed by Alonso's move. Analysing the incident for Channel 4, the Aussie event went as far as to suggest it was dangerous driving on the Spaniard's part.
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He said: "This is a bit personal. We know that these two have a lot of history. Down to the DRS, so they're basically playing, Fernando was trying to manipulate the DRS point, obviously they're into the activation onto this long back straight.
"And when we go on board, watch Fernando in the mirror - he's looking, he's looking, so long, he's actually off the track, he's lifting. That could have got quite embarrassing, but also, [it was] a bit dangerous."
Alonso went on to finish the race seventh, ahead of his rival. Hamilton could only manage ninth at the end of one of the most challenging race weekends the Mercedes driver faced all season, though team-mate George Russell was able to finish third to stand on the podium.