The Citroen driver took advantage after Ford's Jari-Matti Latvala and Petter Solberg retired on stages five and six to move into first place, 36.3 seconds ahead of privateer Evgeny Novikov with Mads Ostberg in third.

Thick fog and heavy rain meant the day's action was cut short after organisers took the decision to cancel stages eight and nine due to safety reasons.

The final stage had already been cancelled due to earlier delays after a car became stuck in a water crossing.

The day started in promising fashion for Ford, with Latvala and team-mate Solberg starting the day in first and second and looking to capitalise on the retirement of championship leader Sebastien Loeb on Thursday night.

However, Latvala's day ended abruptly when his factory Ford slipped off the road on SS5 before Solberg, who had taken the lead as a result, did the same on the next stage.

Safe

It meant Hirvonen was boosted into the lead, and following the early finish, he revealed his decision to play it safe in light of his rivals crashing out.

"It was very, very foggy and very, very muddy as well," the Finn said. "You cannot even believe how slowly we are driving, but it's so slippy that if there's one corner you don't get right, it's over.

"I don't want to take any risks."

Ford Racing manager Gerard Quinn was frustrated after both his cars crashed out, but he remains hopeful that both Latvala and Solberg will restart on day three.

"Disappointed doesn't come close to how we're all feeling," Quinn told www.wrc.com.

"It's actually quite hard to believe what's happened: it's still sinking in. To go from the position we were in last night, first and second, to this...it's unbelievable, particularly with them going out one after another."

"I very much hope that we will see them both out tomorrow and from what we know now, I see no reason why that shouldn't be the case.

"In these situations, the only thing you can do is just get straight back on immediately. There's still a very long way to go."

The rally will resume at 09:49 local time tomorrow with stage 11, the 26.22-kilometre Almodovar test.