LA TOUSSUIRE, France (AFP) - Tour de France leader Chris Froome accused reigning champion Vincenzo Nibali of unsporting behaviour after Friday's 19th stage.
Nibali won the stage after attacking with under 60km to ride just as Froome suffered a mechanical problem.
Italian Nibali had started the day seventh in the standings and more than eight minutes behind Froome, but the Briton still said the move was out of line.
Nibali denied knowing that Froome had a problem and said he was simply implementing his own tactical plan.
But Froome was livid and could be seen berating Nibali after the stage.
"I told him exactly what I thought of him," fumed Froome.
"I think it's pretty self explanatory really. We were going up the last part of the Col de la Croix de Fer, I had a mechanical problem as a small piece of asphalt or a stone got stuck between my derailleur and rear wheel.
"My rear wheel got stuck and I had to get off to fix it. Nibali had the whole climb to attack but chose my mechanical to make his move.
"I heard other riders could see that he turned around and then decided to attack.
"That's not in the spirit of the Tour de France and it's definitely not what this race is about."
Nibali said he hadn't seen Froome and just before he attacked his Astana teammates had been pushing the pace at the front of the peloton.
He had also attacked on the previous climb.
"I won't repeat what he said to me, it was very harsh and unfair," said Nibali.
"He was very angry with me but I didn't understand what his problem was.
"There are many problems in the race, just the other day when (Alberto) Contador crashed we didn't know until 3km-4km later.
"Today the race was on, I didn't know he'd had a problem."
Television images showed Nibali turning around just before he attacked but the Sicilian insisted he hadn't seen Froome.
"When I turned around I spoke to (teammate Tanel) Kangert," said Nibali.
"We wanted to attack on the Col de la Croix de Fer so we were keeping the pace high to try to make it selective."
There is an unwritten rule in cycling not to attack the yellow jersey if he suffers a mechanical problem.
But in the 2010 Tour, Contador did exactly that when Andy Schleck punctured and the Spaniard gained 38sec on his Luxembourg rival that day.
It was the exact amount by which he beat Schleck to win the Tour, although he was later stripped of that victory for doping and the Luxemburger got his Tour win after all.
Nibali is the reigning champion and he was held up by a crash on the second stage in high winds and driving rain in the Netherlands.
The subsequent split in the peloton saw him and Nairo Quintana, lose a minute and a half to Froome for something that wasn't either of their fault.
But Froome insisted the two incidents were different.
"I don't think either of them were in the leader's jersey at that point," said Froome sarcastically.
"It would be the same as on the cobbles, we know in a crosswind stage in the rain you need to be at the front.
"If you're caught in a crash that's racing, the race isn't going to slow down for you, no matter who you are at that point.
"I felt very strongly in the mountains that my mechanical provoked his attack - it wasn't like that in the Netherlands, it wasn't as if we heard of the crash and said 'OK guys, push on'.
"It doesn't work like that."