But with Andrea Mabellini, second in the standings ahead of the Zagreb event, crashing out during a drama-filled Saturday, the championship fight has swung towards points leader Miko Marczyk.

Fresh from his maiden ERC win on JDS Machinery Rali Ceredigion last month, Armstrong and co-driver Shane Byrne continued their impressive form to win five of the six challenging sealed-surface stages to lead WRC2 event winner Robert Virves by 27.3sec.

Armstrong headed into the final round facing an outside shot at the title, sitting 20 points behind championship leader Marczyk. But the M-Sport Ford World Rally Team driver’s performance has left the Irishman firmly in title fight heading into Sunday’s deciding four stages. 

However, Marczyk remains the favourite to lift the title by ending Saturday in sixth place after Mabellini, who started the event two points behind, crashed out on SS4.

Armstrong, starting fifth on the road, set a blistering pace across the morning’s three stages to complete a clean sweep of wins and put his Pirelli-shod Ford Fiesta Rally2 into a 22.5sec lead ahead of Virves’ Hankook-equipped Škoda Fabia RS Rally2.

Virves slashed Armstrong’s advantage in SS4 to 12.7sec after a front-left tyre deflation slowed the leader. But Armstrong responded by winning SS5 and SS6 to restore and extend his lead to 27.3sec ahead of Sunday’s final day, which is likely to be affected by rain.

“I have not really been thinking about it [the title fight] too much today, but there is still a long way to go and tomorrow the rain is going to come. I had that in mind this afternoon,” said Armstrong.

Mads Østberg, making his 300th rally start, drove his Michelin-fitted Citroën C3 Rally2 to the final podium position, 47.6sec off top spot, after a troubled SS6 for Armstrong’s M-Sport team-mate Romet Jürgenson.

Jürgenson, who finished second in Wales last month, delivered strong pace throughout, with the highlight being a fastest time through SS4 that lifted the Estonian FIA Rally Star driver to third. Although hopes of a podium finish were dented when his Fiesta suffered a front-left tyre deflation on the final stage of the day, dropping him to eighth overall, 1min 45.sec adrift.

Østberg, competing alongside a new co-driver in Irishman Lorcan Moore, had been locked in a battle with Mille Johansson for much of the day. But two spins from Johansson in SS4 and SS6 proved costly as the Swede had to settle for fourth ahead of Norbert Maior, whom he succeeded as Junior ERC champion in 2024.

Championship leader Marczyk completed Saturday’s leg in sixth, 1min 22.1sec, off the lead, after a challenging day despite enjoying the best of the road conditions, particularly during the morning loop. The Škoda Fabia RS Rally2 driver overshot a junction in SS3 while struggling to find a consistent rhythm.

“It was not a good day from my side. The morning was average, but the afternoon was not like I would like. The stages are difficult and there are lots of opportunities to make a mistake,” said Marczyk.

“I decided for the first stage of this loop to be on the safe side but in the second one I was trying to drive better, but the time was not there. Here [in the final stage] I would say it was very tricky and to be in the game I decided to be cautious. I need to sleep well and one more time get into the rhythm which I know we can drive. It will be a different story and it will be different conditions, but I need to come back to driving how I like.”

Some pressure was lifted from Marczyk’s shoulders when nearest title rival Mabellini exited the rally on SS4 after a high-speed speed left his Škoda Fabia RS Rally2 with an oil leak following contact with a rock. Mabellini and co-driver Virginia Lenzi had just moved ahead of Marczyk into fifth, and appeared to be in a prime position to boost their title hopes, that are now over following confirmation they won’t restart on day two.

The top 10 was completed by Norbert Herczig, Jürgenson and Team MRF Tyres duo Lauri Joona and Simone Tempestini, who was delayed by tyre damage and a high-speed spin.

Ferenc Vincze is 11th with Erik Cais 12th after two time-consuming tyre deflations delayed the Czech driver on his debut with Team MRF Tyres. Yuki Yamamoto also lost ground with tyre damage after he’d run in the top 10. He’s 13th overnight followed by ERC newcomer Pablo Sarrazin and Jarosław Kołtun.

Jakub Matulka, who was third fastest in Friday qualifying, retired due to damage sustained from running off the road on SS1. Simon Wagner joined the Polish driver on the retirement list after misjudging a long right hander on SS2.

FIA Rally Star Taylor Gill heads the ERC3 class from championship leader Tymek Abramowski by 39.4sec, while Junior ERC champion Calle Carlberg heads Karl Peder Nordstrand in the ERC4 and Junior ERC standings by 1minute 21.4sec after Tuukka Kauppinen dropped back with a tyre damage and a spin on SS6.

The 2025 ERC season concludes on Sunday with crews set to face four more stages, comprising 55.70 competitive kilometres.