The Finn began the day 11.9sec ahead and steadily edged away as the heavy rain many crews had prepared for largely failed to materialise on the roads around Encarnación.
Pajari increased his cushion on each of the opening three stages before running wide into a ditch on Hohenau and tearing the entire upper plane from his GR Yaris Rally1’s rear wing.
He escaped without significant time loss, but the missing aerodynamic component made the faster sections of the following Trinidad test considerably more difficult.
“On the high-speed it’s a massive difference,” Pajari admitted after reaching midday service. “On one stage we lose the wing, and one stage we even hit some small tree on the way, so it’s a crazy rally.
“Even if the condition isn’t so bad, it’s really demanding.”
Paddon endured a subdued morning by comparison. The New Zealander remained comfortably second but struggled to find the rhythm that had carried him into the rally lead on Friday, with Pajari’s advantage reaching as much as 26.0sec before falling back slightly on Trinidad.
“I’m just struggling for rhythm at the moment,” he conceded after Hohenau. “It is not gelling like yesterday. There is still a long way to go, so I just need to reset.”
Behind the leading pair, Adrien Fourmaux mounted an impressive charge towards third-placed Elfyn Evans.
Evans began Saturday with 55.0sec in hand over the Hyundai driver, but Fourmaux chipped away at that margin throughout the loop. He missed the Bella Vista stage win by just 0.4sec to Evans, then went fastest on both Bella Vista Sur and Hohenau before finishing only 0.3sec behind Sébastien Ogier on Trinidad.
By service, Fourmaux had reduced his deficit to Evans to 31.8sec.
“I cannot play with the weather,” Fourmaux said as the expected rain stayed away. “I just drive with the conditions we have got.”
Evans, meanwhile, deliberately avoided unnecessary risks on roads littered with loose stones following Friday’s widespread puncture problems.
“Adrien’s going hard obviously,” the championship leader said after Trinidad. “We’re not trying hard enough.”
The morning’s conditions posed a strategic headache throughout the field. Several crews had softened their cars in anticipation of substantial rain, while Toyota and M-Sport Ford even fitted snorkels to their Rally1 machines overnight. Instead, Bella Vista, Bella Vista Sur and Hohenau remained predominantly dry before damp and muddy sections finally appeared on Trinidad.
Josh McErlean maintained fifth overall despite struggling with a soft set-up and sits 3min 02.1sec from the lead. Oliver Solberg is sixth, 35.6sec further back, after focusing on preserving tyres and avoiding further trouble following his costly Friday.
Home hero Diego Domínguez continued to carry Paraguayan hopes in seventh overall and at the head of WRC2, although his morning contained the unusual setback of losing his glasses after leaving them on the roof of his car following SS10.
Gus Greensmith sits eighth overall and remains Domínguez’s closest WRC2 pursuer despite battling a worsening brake problem throughout the loop.
Saturday’s opening kilometres also brought further attrition. Romet Jürgenson crashed on Hohenau while running inside the leading WRC2 positions, before Marco Bulacia stopped on the following Trinidad test.