Jari-Matti Latvala's Rally Argentina lead is up to 18 seconds over Petter Solberg after a strong end to the day for the Ford driver.
Latvala started his afternoon with another stage victory on the second run through El Mirador. But he could not repeat his mighty morning performance on the crucial part-asphalt El Condor stage, where a slight error saw him pipped by Sebastien Loeb.
"About 10km into El Condor I was braking too late and I stalled the engine," Latvala explained. "I didn't need to reverse or anything like that, I just lost 2-3s.
"It's been a good day and I'm actually very pleased with the performance today. I was actually enjoying the tarmac."
Nearest rival Solberg (Solberg Citroen) admitted that the asphalt had been his weak point on this leg.
"It's been a very good day," said the Norwegian, who took his 400th World Rally Championship stage win on SS6 Mina Clavero. "It's only on the tarmac that I've lost today. I don't know how to approach it."
Citroen's Sebastien Ogier is half a minute off the lead in third after a spin on El Mirador and a cautious approach to the asphalt element of El Condor. He is still 15s clear of Ford's Mikko Hirvonen, who felt he had the wrong set-up for El Condor's gravel and too much tyre wear when he reached the asphalt.
Loeb's quickest time on El Condor made little difference to the distant position his time control penalty had placed him in.
"The gap is too big for tomorrow," Loeb admitted after ending the day 1m30s away from Latvala. "The situation today was that it was very difficult for anyone to make a big gap to the others. It was not a good day."
The Stobart Fords of Mads Ostberg and Matthew Wilson are sixth and seventh ahead of local hero Federico Villagra (Munchi's Ford).
Amid high attrition in the Production class, an early three-way fight between Patrik Flodin, Michal Kosciuszko and Hayden Paddon has become a dominant lead for the latter.
Leading positions after SS7: Pos Driver Team/Car Time/Gap 1. Jari-Matti Latvala Ford 1h48m59.7s 2. Petter Solberg Solberg Citroen + 18.2s 3. Sebastien Ogier Citroen + 28.8s 4. Mikko Hirvonen Ford + 43.5s 5. Sebastien Loeb Citroen + 1m30.3s 6. Mads Ostberg Stobart Ford + 2m55.2s 7. Matthew Wilson Stobart Ford + 3m27.4s 8. Federico Villagra Munchi's Ford + 3m40.9s 9. Ken Block Monster Ford + 6m04.8s 10. Hayden Paddon Symtech Subaru + 11m49.6s