Sebastien Loeb moved 40 seconds clear of Sebastien Ogier as the Rally Argentina drama continued on Friday afternoon.
But after gaining by several seconds early on the stage, Ogier's Volkswagen picked up a puncture near the finish, losing a further 3.4s.
With only one spare left and Loeb not a championship threat, Ogier elected to back off on the following Amboy stage, leaving the Citroen clear to open up a dominant lead.
Ogier's need to push was reduced by multiple problems for Loeb's title-chasing team-mate Mikko Hirvonen.
Like Ogier, Hirvonen had a puncture on Santa Rosa, but further from the finish and in more spectacular fashion.
That cost him 40s and dropped him to third. Worse was to follow as a recurring electronic problem meant the Citroen kept cutting out on Amboy.
Hirvonen lost a full six minutes and is now back in sixth place.
Jari-Matti Latvala had closed to within 10s of Hirvonen when the Citroen picked up its puncture, encouraging the VW driver to mount a charge for third place.
Hirvonen's electrical issue would ultimately mean Latvala could have taken it easy - but by that time things had already gone awry, as a heavy landing over a jump on SS9 gave Latvala a puncture too.
He had to stop and change the wheel, losing two minutes.
All of that elevated M-Sport Ford driver Evgeny Novikov into third place.
His team-mate Thierry Neuville also benefited. The Belgian had started the afternoon steadily losing ground to VW's Andreas Mikkelsen in their battle for what was then sixth.
But Mikkelsen's rapid pace on Santa Rosa - where he was third quickest - came at a price. An impact along the way gave his VW suspension damage that forced his retirement after the finish.
Neuville therefore found himself in fifth place by the time SS9 was over.
The drivers are now heading back to the superspecial for a Friday evening run to conclude the leg.
Leading positions after SS9: Pos Driver Team/Car Time/Gap 1. Sebastien Loeb Citroen 3h27m25.0s 2. Sebastien Ogier VW + 40.3s 3. Evgeny Novikov M-Sport Ford + 2m39.5s 4. Jari-Matti Latvala VW + 2m53.0s 5. Thierry Neuville M-Sport Ford + 3m31.1s 6. Mikko Hirvonen Citroen + 6m41.9s 7. Mads Ostberg M-Sport Ford + 10m40.1s 8. Martin Prokop Czech Ford + 11m59.2s 9. Dani Sordo Citroen + 13m01.1s 10. Gabriel Pozzo M-Sport Ford + 14m30.2s