Jan Kopecky completed leg one of the Croatia Rally by celebrating winning the FIA European Rally Championship for the first time.

Kopecky's Skoda Motorsport team has officially acknowledged his and co-driver Pavel Dresler's standout achievement after they added a further seven points to their dominant total score by topping the classification at the overnight halt in host town Porec on the banks of the Adriatic Sea.

Driving a Fabia Super 2000 on Michelin tyres, Kopecky was fastest on the day's final four stages to hold a winning margin of 52.9s starting Saturday's final leg. However, the Czech driver spent much of the day playing catch up after ERC Production Car Cup contender Andreas Aigner shot into the overall lead by winning Friday's opening stage in wet conditions in his near-standard-specification Subaru Impreza R4 STI.

While the bulk of the frontrunners opted for hard compound tyres in the belief it would be dry, heavy showers turned the leaderboard on its head with Aigner and Hermann Gassner Jr going first and second quickest on the rain-hit Boljun test this morning, while Sebastian Barbu and Kornel Lukacs also excelled in their front-wheel-drive cars in third and fourth respectively. All four drivers had fitted tyres better suited to the wet weather and experienced much better grip as a result.

And it would get better for Aigner when he went fastest again on stage three. Although Kopecky hit back on the day's mainly dry third stage, it was Aigner who was in front at midday service in Porex with a margin of 10.5s. "I did not expect to be leading for sure and my aim is to score as many points as possible in the ERC Production Car Cup," said Aigner, whose Stohl Racing-run Subaru runs on Yokohama tyres. "It feels nice but I don't expect it to continue because Jan will be very fast this afternoon."

With the stages continuing to dry out in the afternoon, Kopecky made the performance advantage of his Fabia count to catch and pass Aigner for first place. Gassner Jr completed leg one in third, 5.2s behind Aigner.

"It has not been easy for me today but winning the title is a dream come true for me," said Kopecky. "I would like to thank Skoda Motorsport and our fantastic team for the amazing work they have done this season."

Skoda Motorsport head Michal Hrabanek added: "With the ERC title for Jan Kopecky and Pavel Dresler, we have claimed another major success for the Skoda Fabia Super 2000 project. Our entire team has worked hard all year to achieve this goal. This is a wonderful reward for everyone involved. We have once again proven the quality of the Fabia Super 2000 and the technical expertise of Skoda."

While Aigner might have lost his early lead, the Austrian will move back ahead of Jarslav Orsak in the race for the ERC Production Car Cup if he maintains his advantage during leg two.

Orsak is not competing in Croatia for medical reasons while Germain Bonnefis, another title contender, retired on stage three after crashing his Renault Megane Renaultsport RS. The rising French star confirmed he suffered a fractured vertebra in the accident. He has been released from hospital following treatment and is expected to make a full recovery.

Bernd Casier completed leg one in fourth overall and will now hand over driving duties to Pieter Tsjoen for Saturday's stages. The Belgians are sharing driving and co-driving duties and it will be Casier's turn co-driving on day two.

Triple Croatia Rally winner Juraj Sebalj, who led after Thursday evening's superspecial stage in Porec, is fifth overnight after dropping time in the wet conditions this morning. South African teenager Henk Lategan is an impressive sixth on his second rally on asphalt. Aleks Humar is seventh with Andras Hadik eighth. Daniel Saskin is ninth on his debut in a Ford Fiesta RRC with Hermann Gassner Sr tenth.

Aleks Humar meanwhile heads the ERC 2WD Championship contenders with Asja Zupanc on top in the ERC Ladies' Trophy battle.

Leg two features seven stages over a competitive distance of 120.44 kilometres and begins with the 14.97-kilometre Butoniga stage at 10:04hrs local time on Saturday.