Sebastien Loeb accused Mikko Hirvonen of deliberately delaying him when the Ford rejoined after changing a puncture on SS9 in Portugal.
Hirvonen had to change the tyre on the Vascao stage, leaving him two minutes off his rally-leading team-mate Jari-Matti Latvala.
The Ford rejoined as soon as the new tyre was fitted, and Hirvonen felt he was far enough ahead of Loeb not to hold the Citroen up - but the Frenchman vehemently disageed. Loeb lost time on the stage and is now 32.5 seconds away from the lead, blaming the delay from running in Hirvonen's dust.
"He had the puncture and started eight seconds in front of me, and he didn't let me past to protect Jari-Matti," said Loeb. "For sure it's a good strategy for Ford, but it's destroyed my race. I didn't have a puncture, he did."
Loeb nudged Hirvonen car after the end of the stage to express his displeasure, but Hirvonen was adamant he had done nothing wrong and had been sufficiently clear of Loeb when he restarted.
"I'm sure Sebastien's really, really mad," said Hirvonen. "I'm sorry about that, but when I've changed the tyres, I go. That's how the rules are now."
The incident has allowed Latvala and Citroen's Sebastien Ogier to break away the front of the field, with 5.6sec between them now.