Türkkan emerged from an attritional second day 21.9sec clear of Leevi Lassila, having won four of Saturday’s six stages as the championship pendulum swung dramatically in his direction.
Carlberg, who arrived at the season finale three points ahead of Türkkan, had remained firmly in contention through the morning and won the first pass of María las Cruces. But the Swede rolled heavily on SS11, Lota 2, ending his rally.
Carlberg and co-driver Jørgen Eriksen were taken to hospital for precautionary checks and will take no further part in the event.
That incident could prove decisive in a title contest which began the weekend with five drivers mathematically in contention.
Carlberg started Chile on 95 points to Türkkan’s 92. He added two stage-win bonus points on Friday and another on Saturday morning, meaning he can retain those three points despite his retirement and ends his scoring opportunity on 98.
Türkkan, meanwhile, has added four stage wins on Saturday alone and now effectively sits on 96 points before any Chile classification score is applied.
With classification points doubled at the finale - 50 for victory, 36 for second, 30 for third and 24 for fourth - and only each driver’s best four rally classification results counting, a finish on Sunday would put Türkkan in a commanding position to seal the title.
The reward is significant: the 2026 Junior WRC champion earns four fully funded WRC2 rounds in 2027, including testing, in an M-Sport-run Ford Fiesta Rally2.
Türkkan’s route to the overnight lead was far from straightforward.
Lassila started Saturday at the head of the standings and survived a roll on the first pass of María las Cruces. An optimistic pace note left the Finn carrying too much speed through a tightening sequence, but his Fiesta Rally3 landed back on its wheels and escaped with mainly bodywork damage.
Despite the incident, Lassila retained the lead through SS10, although Türkkan had reduced the gap to just 1.6sec after winning both Pelún and Lota during the morning.
Türkkan then struck decisively on the second Lota run. His fourth stage victory of the day was 24.0sec faster than Lassila and promoted him into the lead, before a more measured approach on María las Cruces left him 21.9sec clear overnight.
The Turkish driver had deliberately backed off on the morning’s first pass through María las Cruces after encountering an issue with his wheel gun, unwilling to risk a puncture which he might not have been able to change.
Behind the leading pair, Craig Rahill produced an increasingly assured Saturday and was rewarded with fastest time on the final stage. The Irishman occupies third, 3min 52.0sec behind Türkkan.
Gil Membrado’s championship ambitions suffered an even earlier blow. The Spaniard rolled on SS7 but initially lost only 37.6sec after landing back on his wheels. Damage to the intercooler then left his Fiesta significantly down on power and cost more than four minutes on the following stage.
Membrado battled on to finish Saturday fourth, 9min 23.4sec from the lead.
Sunday brings 71.2 competitive kilometres across four stages, with two runs each through the new Carampangue test and BIOBÍO, the latter hosting the rally-ending Wolf Power Stage.