Jose Maria Lopez delighted his home crowd by taking his sixth World Touring Car Championship victory of the season in race one at Termas de Rio Hondo.
Returning to the venue of his attention-grabbing (and race-winning) WTCC debut in 2013, Lopez led every lap from pole, in front of a crowd including fans who had travelled 2000 kilometres to the track in northern Argentina. His faultless performance also included fastest lap.
The Argentinean's closest title rival and Citroen team-mate Yvan Muller suffered a poor start from the front row. After immediately dropping behind fast-starting Zengo Motorsport man Norbert Michelisz, Muller was forced to concede third place on the inside of Turn 1 by a late-braking Tiago Monteiro.
Both Muller and the third C-Elysee of Sebastien Loeb used their straightline speed advantage to recover their positions from Monteiro before the completion of the opening lap.
Lopez and Michelisz were the only drivers lapping in the 1m46s during the first half of the race, with the Hungarian initially staying in touch with the leader.
At the chequered flag he dropped to 2.5 seconds in arrears after coming under late pressure from a recovering Muller, though second was still Michelisz's season-best.
Fourth place was closely contested by Loeb, Monteiro and ROAL Motorsport's Tom Chilton.
The trio were covered by less than two seconds at the finish, but despite running in close proximity throughout there was no change in order after the opening tour.
Monteiro's progress was restricted by a broken shock-absorber on lap five.
The effects of Lada's summer development programme and weight shedding were visible as the Russian manufacturer enjoyed one of its strongest showings of the season.
Former WTCC champion Rob Huff held off the factory Honda of Gabriele Tarquini for seventh, while team-mate James Thompson snatched 10th position from Tom Coronel at the hairpin on the last lap.
Both Campos Chevrolet drivers ended race one in the pits. Race two front row starter Hugo Valente endured a trip across the grass on lap one, and later received a tap from Mikhail Kozlovskiy's Lada.
Results - 13 laps:
Pos Driver Team/Car Time/Gap
1. Jose Maria Lopez Citroen 23m10.174s
2. Norbert Michelisz Zengo Honda +2.526s
3. Yvan Muller Citroen +3.271s
4. Sebastien Loeb Citroen +7.613s
5. Tiago Monteiro Honda +8.871s
6. Tom Chilton ROAL Chevrolet +9.508s
7. Rob Huff Lada +13.893s
8. Gabriele Tarquini Honda +14.494s
9. Mehdi Bennani Proteam Honda +17.929s
10. James Thompson Lada +25.133s
11. Tom Coronel ROAL Chevrolet +25.272s
12. Gianni Morbidelli Munnich Chevrolet +26.707s
13. Rene Munnich Munnich Chevrolet +27.483s
14. Mikhail Kozlovskiy Lada +29.031s
15. Franz Engstler Engstler BMW +1m18.040s*
16. John Filippi Campos SEAT +1m26.442s*
17. Camilo Echevarria Engstler BMW -1 lap*
Dusan Borkovic Campos Chevrolet 8 laps
Hugo Valente Campos Chevrolet 7 laps